Pepper(Capsicum annuum L.)is a typical self-pollinating crop with obvious heterosis in hybrids.Consequently,the use of morphological markers during the pepper seedling stage is crucial for pepper breeding.The color of...Pepper(Capsicum annuum L.)is a typical self-pollinating crop with obvious heterosis in hybrids.Consequently,the use of morphological markers during the pepper seedling stage is crucial for pepper breeding.The color of hypocotyl is widely used as a phenotypic marker in crossing studies of pepper.Pepper accessions generally have purple hypocotyls,which are mainly due to the anthocyanin accumulation in seedlings,and green hypocotyls are rarely observed in pepper.Here we reported the characterization of a green hypocotyl mutant of pepper,Cha1,which was identified from a pepper ethyl methanesulfonate(EMS)mutant library.Fine mapping revealed that the causal gene,CaTTG1,belonging to the WD40 repeat family,controlled the green hypocotyl phenotype of the mutant.Virus-induced gene silencing(VIGS)confirmed that CaTTG1 regulated anthocyanin accumulation.RNA-seq data showed that expression of structural genes CaDFR,CaANS,and CaUF3GT in the anthocyanin biosynthetic pathway was significantly decreased in Cha1 compared to the wild type.Yeast two-hybrid(Y2H)experiments also confirmed that CaTTG1 activated the synthesis of anthocyanin structural genes by forming a MBW complex with CaAN1 and CaGL3.In summary,this study provided a green hypocotyl mutant of pepper,and the Kompetitive Allele Specific PCR(KASP)marker developed based on the mutation site of the underlying gene would be helpful for pepper breeding.展开更多
Melon is a globally cultivated horticultural crop with a predominantly hybrid commercial seed market in China.Seedling morphology,particularly hypocotyl color,is a valuable trait for rapid F1 hybrid seed purity assess...Melon is a globally cultivated horticultural crop with a predominantly hybrid commercial seed market in China.Seedling morphology,particularly hypocotyl color,is a valuable trait for rapid F1 hybrid seed purity assessment.While green hypocotyls are common,white hypocotyls are rare in melon germplasm.This study identified a mutant with white hypocotyl but green leaves from the heavy ion beam mutant library.Genetic analysis revealed that a single recessive gene controlled the white hypocotyl,designated CmGhc1.A single-base deletion in the fifth exon of CmGhc1 led to a truncated CmGhc1 lacking the HTH-MYB DNA binding domain,likely affecting its transcriptional activity.CmGhc1 was localized in the nucleus,and yeast two-hybrid analysis and a dual-LUC assay demonstrated it as a transcription repressor.Furthermore,a KASP marker(hc1)was developed and verified as a functional marker for breeding white hypocotyl germplasms in melon.RNA-seq data revealed that CmGhc1 significantly affected the transcription of genes related to chlorophyll metabolism and photosynthesis in hypocotyl.In summary,these findings contribute to our understanding of chloroplast biogenesis and provide a valuable tool for melon breeding.展开更多
Hypocotyl length is regarded to be a crucial seedling trait,influencing many subsequent plant development processes.However,little is known about this trait in Brassica campestris syn.Brasscia rapa.Here,we performed a...Hypocotyl length is regarded to be a crucial seedling trait,influencing many subsequent plant development processes.However,little is known about this trait in Brassica campestris syn.Brasscia rapa.Here,we performed a comparative observation on the early hypocotyl development between two cultivars,‘SZQ’belonging to pak-choi(B.campestris ssp.chinensis var.communis)with longer hypocotyls,and‘WTC’belonging to Tacai(B.campestris L.ssp.chinensis var.rosularis)with shortter hypocotyls,and found that the difference in auxin biosynthesis might contribute to the varied hypocotyl phenotype between these two cultivars.By applying GWAS analysis using a total of 226 B.campestris accessions,we identified that the AT-Hook motif nuclear localized(AHL)gene BcAHL24-MF1 contributed to the natural variation in hypocotyl length.Functional variation of BcAHL24-MF1 was attributed to four haplotypes featuring four SNPs within the promoter region,of which Hap I accumulated more transcripts with shorter hypocotyls.Constitutive overexpression of BcAHL24-MF1 in B.campestris caused decreased hypocotyl length under light circumstances and even constant darkness,as BcAHL24-MF1 repressed the PIFmediated transcriptional activation of auxin biosynthesis genes BcYUC6-MF2 and BcYUC8-LF.Our research uncovered the important role of BcAHL24-MF1 in regulating light-triggered inhibition of hypocotyl elongation,therefore presenting a valuable genetic target for crop breeding.展开更多
The plasma membrane vesicles were purified from soybean (Glycine max L.) hypocotyls by two_phase partitioning methods. The stimulatory effects of K + on the coupling between ATP hydrolysis and proton transport by th...The plasma membrane vesicles were purified from soybean (Glycine max L.) hypocotyls by two_phase partitioning methods. The stimulatory effects of K + on the coupling between ATP hydrolysis and proton transport by the plasma membrane H +_ATPase were studied. The results showed that the proton transport activity was increased by 850% in the presence of 100 mmol/L KCl, while ATP hydrolytic activity was only increased by 28.2%. Kinetic studies showed that K m of ATP hydrolysis decreased from 1.14 to 0.7 mmol/L, while V max of ATP hydrolysis increased from 285.7 to 344.8 nmol Pi·mg -1 protein·min -1 in the presence of KCl. Experiments showed that the optimum pH was 6.5 and 6.0 in the presence and absence of KCl, respectively. Further studies revealed that K + could promote the inhibitory effects of hydroxylamines and vanadates on the ATP hydrolytic activity. The above results suggested that K + could regulate the coupling between ATP hydrolysis and proton transport of the plasma membrane H +_ATPase through modulating the structure and function of the kinase and phosphatase domains of the plasma membrane H +_ATPase.展开更多
The stimulatory effect of lysophosphatidylcholine (lyso_PC) on ATP and ρ_nitrophenyl phosphate (PNPP) hydrolysis by the plasma membrane H +_ATPase from soybean (Glycine max (L.) Merr.) hypocotyls was studied. Re...The stimulatory effect of lysophosphatidylcholine (lyso_PC) on ATP and ρ_nitrophenyl phosphate (PNPP) hydrolysis by the plasma membrane H +_ATPase from soybean (Glycine max (L.) Merr.) hypocotyls was studied. Results showed that lyso_PC stimulated the hydrolysis of ATP; ATP hydrolysis was enhanced dramatically when lyso_PC was within 0-0.03%, and increased slightly when lyso_PC was higher than 0.03%. At the concentration of 0.03%, lyso_PC stimulated ATP hydrolysis by 80.5%. Kinetics analysis showed that V max increased from 0.46 μmol P i·mg -1 protein·min -1 to 0.87 μmol P i·mg -1 protein·min -1 while K m increased from 0.88 mmol/L to 1.15 mmol/L under lyso_PC treatment. The optimum pH of ATP hydrolysis was shifted from 6.5 to 7.0 . Moreover, it was found lyso_PC enhanced the inhibition of ATP hydrolysis by hydroxylamine. In the presence of 200 mmol/L hydroxylamine, ATP hydrolysis was inhibited by 74.4%, while it was inhibited by 84.4% when treated with lyso_PC. However, PNPP hydrolysis and the inhibitory effect of vanadate were not affected by lyso_PC. The above results indicated that the kinase domain might be an action site or regulatory region of the C_terminal autoinhibitory domain in the plant plasma membrane H +_ATPase.展开更多
[Objective] This study aimed to investigate rapid multiplication of Apocynum by tissue culture so as to provide plantlet sources for its industrialized cultivation. [Method] The asepsis seedlings were obtained by deal...[Objective] This study aimed to investigate rapid multiplication of Apocynum by tissue culture so as to provide plantlet sources for its industrialized cultivation. [Method] The asepsis seedlings were obtained by dealing with Apocynum seeds. Its cotyledons, hypocotyls and shoot tips were cultured on the media containing different concentrations of hormones. Finally, the influence of different hormone combinations on differentiation of cotyledons and hypocotyls, rapid multiplication of shoot tips, rapid multiplication of regenerated shoots, and rooting of test-tube plantlets was com- pared. [Result] MS＋2.0 mg/L BA＋0.03 mg/L NAA and MS＋0.07 mg/L NAA were the optimum medium for inducing regenerated buds from cotyledons and hypocotyls re- spectively; MS＋2.0 mg/L BA＋0.02 mg/L NAA was the best medium for rapid multi- plication of shoot tips; MS＋1.9 mg/L BA＋I.7 mg/L NAA was the best medium for rapid multiplication of regenerated buds： and 1/2MS＋0.6 mg/L NAA was the best medium for inducing roots. [Conclusion] The optimum hormone combination was de- termined for Apocynum rapid multiplication by tissue culture, which provides technical support on Apocynum industrialized cultivation.展开更多
An efficient plant regeneration protocol was established for castor bean （Ricinus communis L.）, in which 0.3 mg L-1 thidiazuron （TDZ） induced shoot clusters and increased the number of adventitious shoots from hyp...An efficient plant regeneration protocol was established for castor bean （Ricinus communis L.）, in which 0.3 mg L-1 thidiazuron （TDZ） induced shoot clusters and increased the number of adventitious shoots from hypocotyl tissue. Our results showed that treatment under dark conditions significantly promoted the average number of shoots per explant to 37.36±4.54 （with a 6-d treatment）. Modified 1/2 Murashige and Skoog （MS） basal medium supplemented with 440 mg L-1 Ca2＋, 0.2 mg L-1 gibberellic acid and 0.1 mg L-1 TDZ significantly increased shoot elongation rates and lowered vitrification rates. Further- more, 1/2 MS media supplemented with 0.2 mg L-11-naphthaleneacetic acid induced a higher rooting rate compared with other culture conditions.展开更多
Ambient temperature induces the hypocotyl elongation of seedling,called as thermomorphogenesis.It has been reported that the bHLH transcriptional factor PIF7 acts as the critical component to modulate plant thermomorp...Ambient temperature induces the hypocotyl elongation of seedling,called as thermomorphogenesis.It has been reported that the bHLH transcriptional factor PIF7 acts as the critical component to modulate plant thermomorphogenesis,but the underlying mechanism remains elusive.The phytohormone abscisic acid(ABA)suppresses the hypocotyl elongation under high temperature(HT)stress.As the ABI5 binding protein,AFP2 acts as the negative factor to control ABA signaling.In this study,we first identified AFP2 as the interaction protein of PIF7 in vitro and in vivo.Phenotype analysis revealed that overexpressing AFP2 reduced the hypocotyl elongation,while loss-of-function afp2 mutant showed longer hypocotyl under HT.Consistently,overexpressing AFP2 impaired the transactivation effect of PIF7 on auxin biosynthesis related genes YUC8 and IAA19,which possibly resulted into the shorter hypocotyl in the transgenic line overexpressing AFP2 or co-overexpressing AFP2 and PIF7.Thus,these data suggest that AFP2 suppressed PIF7 activity to suppress hypocotyl elongation.Furthermore,we found that HT gradually induced the degradation of AFP2 that possibly released the inhibitory effect of AFP2 on PIF7,thus induced hypocotyl elongation under HT.Taken together,our result reveals the novel function of AFP2 in coordinating thermomorphogenesis through sophistically modulating PIF7 activity.展开更多
Seeds of soybeans and mung beans were soaked into five different concentrations （0, 0.05, 0.10, 0.20, 0.30 mg/L） of natural brassinolide （ NBR ） solution. According to the results, natural brassinolide treatment c...Seeds of soybeans and mung beans were soaked into five different concentrations （0, 0.05, 0.10, 0.20, 0.30 mg/L） of natural brassinolide （ NBR ） solution. According to the results, natural brassinolide treatment could improve seed germination rate and hypocotyl-radicle ratio of soybeans and mung beans and promote the growth of sprouts. To be specific, seed germination rate of soybeans reached the highest in 0.05 mg/L natural brassinolide treatment, which was im- proved by 25.0 percentage points compared with the control group, and the sprout length was improved by 4.33 em; 0.30 mg/L natural brassinolide exhibited the most significant promotion effect on seed germination and sprout growth of mung beans, seed germination rate was improved by 18.3 percentage points and sprout length was improved by 7.29 cm; hypocotyl-radiele ratio of soybean and mung bean sprouts reached the highest （2.96, 1.43 ） in 0.05 mg/L natural brassinolide treatment.展开更多
The germination capacity of Ailanthus altissima seeds improved after the seeds were soaked with different concentrations of natural brassinolide （NBR）. The germination rate and germination energy of the seeds increa...The germination capacity of Ailanthus altissima seeds improved after the seeds were soaked with different concentrations of natural brassinolide （NBR）. The germination rate and germination energy of the seeds increased by 17.6% and 18.8%, and the mean germination speed （i.e., germination time） of the seeds was shortened by 1.4 d under the optimal concentration （0.4 mg·L^-1） treatment, compared with the control. After hypocotyls of A.altissima were treated with NBR, the elongation of the hypocotyls increased. Among different concentrations of the NBR, 0.4 mg·L^-1 NBR appeared to be the optimal concentration for the elongation of A.altissima hypocotyls.展开更多
The COP9 signalosome （CSN） is a multiprotein complex which participates in diverse cellular and developmental processes. CSN1, one of the subunits of CSN, is essential for assembly of the multiprotein complex via P...The COP9 signalosome （CSN） is a multiprotein complex which participates in diverse cellular and developmental processes. CSN1, one of the subunits of CSN, is essential for assembly of the multiprotein complex via PCI （proteasome, COP9 signalosome and initiation factor 3） domain in the C-terminal half of CSN 1. However, the role of the N-terminal domain （NTD） of CSN 1, which is critical for the function of CSN, is not completely understood. Using a yeast two-hybrid （Y2H） screen, we found that the NTD of CSN1 interacts with TSK-associating protein 1 （TSA1）, a reported CaZ＋-binding protein. The interaction between CSN1 and TSA1 was confirmed by co-immunoprecipitation in Arabidopsis. tsal mutants exhibited a short hypocotyl phenotype in darkness but were similar to wild-type Arabidopsis under white light, which suggested that TSA1 might regulate Arabidopsis hypocotyl development in the dark. Furthermore, the expression of TSA1 was significantly lower in a csnl null mutant （fus6）, while CSN1 expression did not change in a tsal mutant with weak TSAI expression. Together, these findings suggest a functional relationship between TSAI and CSN1 in seedling development.展开更多
We studied the roles of different concentrations of gibberellin A_(3)(GA_(3))in breaking hypocotyl dormancy of Paeonia anomala subsp.veitchii,aiming to provide a theoretical basis for the efficient elimination of seed...We studied the roles of different concentrations of gibberellin A_(3)(GA_(3))in breaking hypocotyl dormancy of Paeonia anomala subsp.veitchii,aiming to provide a theoretical basis for the efficient elimination of seed dormancy.The seeds of P.anomala subsp.veitchii were treated with different concentrations of GA_(3)(0,100,200,300,and 400 mg/L)under dark conditions at 16℃,and then the rooting indicators including rooting rate,rooting vigor,rooting index and mold rot rate were determined.The treatment with 400 mg/L GA_(3) for 4 h showed the best performance in breaking the hypocotyl dormancy.Specifically,the treatment shortened the rooting time to 12 d,increased the rooting rate,rooting vigor,and rooting index to 84.00%±5.29%,80.67%±5.03%,and 2.25±0.16 respectively,and decreased the mold rot rate to 0.67%±1.16%.To sum up,there were germination inhibitors in the seeds of P.anomala subsp.veitchii,while the addition of exogenous hormone GA_(3) can release the inhibitory effect on the hypocotyl,which indicated that GA_(3) can promote the breaking of hypocotyl dormancy.展开更多
Ethylene plays essential roles in plant growth,development and stress responses.The ethylene signaling pathway and molecular mechanism have been studied extensively in Arabidopsis and rice but limited in peanuts.Here,...Ethylene plays essential roles in plant growth,development and stress responses.The ethylene signaling pathway and molecular mechanism have been studied extensively in Arabidopsis and rice but limited in peanuts.Here,we established a sand-culture method to screen pingyangmycin mutagenized peanut lines based on their specific response to ethylene(“triple response”).An ethylene-insensitive mutant,inhibition of peanut hypocotyl elongation 1(iph1),was identified that showed reduced sensitivity to ethylene in both hypocotyl elongation and root growth.Through bulked segregant analysis sequencing,a major gene related to iph1,named AhIPH1,was preliminarily mapped at the chromosome Arahy.01,and further narrowed to a 450-kb genomic region through substitution mapping strategy.A total of 7014 genes were differentially expressed among the ACC treatment through RNA-seq analysis,of which only the Arahy.5BLU0Q gene in the candidate mapping interval was differentially expressed between WT and mutant iph1.Integrating sequence variations,functional annotation and transcriptome analysis revealed that a predicated gene,Arahy.5BLU0Q,encoding SNF1 protein kinase,may be the candidate gene for AhIPH1.This gene contained two single-nucleotide polymorphisms at promoter region and was more highly expressed in iph1 than WT.Our findings reveal a novel ethylene-responsive gene,which provides a theoretical foundation and new genetic resources for the mechanism of ethylene signaling in peanuts.展开更多
Adventitious shoots were successfully regenerated from hypocotyl explants of in vitro cultures of Euonymus japonicus Cu zhi. Hypocotyl slices were cultured on Murashige and Skoog （MS） and B5 basal medium supplemente...Adventitious shoots were successfully regenerated from hypocotyl explants of in vitro cultures of Euonymus japonicus Cu zhi. Hypocotyl slices were cultured on Murashige and Skoog （MS） and B5 basal medium supplemented with varied concentration of different plant growth-regulators, e.g., α-naphthaleneacetic acid （NAA） and indole-3-butyric acid （IBA） in combination with 6-benzylaminopurine （6-BA） and kinetin. The study showed that shoots could be directly regenerated from hypocotyl explants without the intervening callus phase; MS medium was more suitable for adventitious shoots regeneration. The ability of hypocotyls segments to produce shoots varied depending upon their position on the seedlings. The highest regeneration rate was obtained with hypocotyl segments near to the cotyledon cultured on MS basal medium supplemented with 1.5 mg L^-1 6-BA and 0.05 mg L^-1 NAA （63.64%）. The regenerated shoots were readily elongated on the same medium as used for multiplication and rooted on half-strength MS basal medium supplemented with 1.0 mg L^-1 IBA and 100 mg L^-1 activated carbon. After being transferred to greenhouse conditions, 96% of the plantlets were successfully acclimatized. This regeneration system is applied for genetic transformation now.展开更多
The influence of humic substances (HS) formulations derived from sedimentary and compost sources was studied on plant growth at cell level and chlorophyll retention during accelerated senescence of leaf tissue. The di...The influence of humic substances (HS) formulations derived from sedimentary and compost sources was studied on plant growth at cell level and chlorophyll retention during accelerated senescence of leaf tissue. The direct effect of HS formulations was studied on cell expansion using cucumber and radish cotyledon expansion test. The cucumber hypocotyl elongation test was used to study the effect on cell elongation. Chlorophyll pigment retention in excised leaf tissue incubated in dark with high temperature was assessed to study the effect on leaf senescence. Explant tissues were incubated directly in the solutions of the formulations at the concentration recommended for foliar application to the crop plants. HS formulations showed significant variations in their direct bio-stimulatory effects. Formulations derived from compost sources were found superior in terms of inducing a direct stimulatory effect on cell expansion and cell elongation and in maintaining chlorophyll pigment retention during accelerated senescence. HS from sedimentary sources stimulated cell expansion and delayed chlorophyll degradation to a lesser extent compared to HS from compost. However, HS formulations derived from sedimentary sources used in this study were not effective in inducing cell elongation in the cucumber hypocotyl elongation test. The direct bio-stimulatory effect of HS formulations differed significantly between the formulations that were evaluated.展开更多
Santalum album L.is a commercially important tree that yields essential oil of high medicinal value.Regeneration research through organogenesis and embryogenesis has been documented but no report depicts comparative o...Santalum album L.is a commercially important tree that yields essential oil of high medicinal value.Regeneration research through organogenesis and embryogenesis has been documented but no report depicts comparative ontogeny of directly differentiating shoot buds(SB)and somatic embryos(SE).In the present study aseptic seedling derived hypocotyl segments(HC)and hypocotyl+root junction(HC+R)were used to induce SBs and SEs,respectively.Ontogenic differences between the structures were confirmed using scanning electron microscopy and histological analysis.MS medium containing 6-benzyladenine or BA(2.5μM)produced highest number of direct SB,while MS+BA(7.5μM)proved suitable for higher frequency of SE differentiation.The differentiating structures attained growth when transferred to MS medium containing a combination of BA and anaphthalene acetic acid or silver nitrate(AgNO3).A combination of indole-3-butyric acid and silver nitrate(AgNO3)in half-strength woody plant medium and lesser osmotic concentration(2%sucrose),induced rhizogenesis.展开更多
Gravitropic curvature growth of Arabidopsis hypocotyls mainly occurred in the rapid growing Elongation Zone(EZI),not in the slow-growing Elongation Zone(EZII).By examining reorientation of Microtubules(MT)and phenotyp...Gravitropic curvature growth of Arabidopsis hypocotyls mainly occurred in the rapid growing Elongation Zone(EZI),not in the slow-growing Elongation Zone(EZII).By examining reorientation of Microtubules(MT)and phenotype of the cell wall in the EZI and the EZII of Arabidopsis hypocotyls under normal gravitational condition,it is found that MTs in the rapid growing epidermal cells were mainly in the transverse direction,while those in the non-growing epidermal cells were in the longitudinal directions.However,this difference in cortical MT arrays between the EZI and EZII cells disappeared when the seedlings were exposed to the simulated microgravity condition on a horizontal clinostat.Field emission scanning electron microscopy revealed that the surface texture of epidermal cells,like the direction of the MT,in the EZI and the EZII also became similar when exposed to the simulated microgravity condition.This result indicated that simulate microgravity could modify the potential differentiation between the EZI and the EZII by affecting the orientation of cortical MT in the epidermal cells.展开更多
基金supported by grants from the Special Funds for Construction of Innovative Provinces in Hunan Province(Grant No.2021NK1006)the Science and Technology Innovation Program of Hunan Province(Grant No.2021JC0007)+2 种基金China Agriculture Research System of MOF and MARA(Grant No.CARS-24-A-15)National Natural Science Foundation of China(Grant No.32130097)National Natural Science Foundation of China(Grant No.U19A2028)。
文摘Pepper(Capsicum annuum L.)is a typical self-pollinating crop with obvious heterosis in hybrids.Consequently,the use of morphological markers during the pepper seedling stage is crucial for pepper breeding.The color of hypocotyl is widely used as a phenotypic marker in crossing studies of pepper.Pepper accessions generally have purple hypocotyls,which are mainly due to the anthocyanin accumulation in seedlings,and green hypocotyls are rarely observed in pepper.Here we reported the characterization of a green hypocotyl mutant of pepper,Cha1,which was identified from a pepper ethyl methanesulfonate(EMS)mutant library.Fine mapping revealed that the causal gene,CaTTG1,belonging to the WD40 repeat family,controlled the green hypocotyl phenotype of the mutant.Virus-induced gene silencing(VIGS)confirmed that CaTTG1 regulated anthocyanin accumulation.RNA-seq data showed that expression of structural genes CaDFR,CaANS,and CaUF3GT in the anthocyanin biosynthetic pathway was significantly decreased in Cha1 compared to the wild type.Yeast two-hybrid(Y2H)experiments also confirmed that CaTTG1 activated the synthesis of anthocyanin structural genes by forming a MBW complex with CaAN1 and CaGL3.In summary,this study provided a green hypocotyl mutant of pepper,and the Kompetitive Allele Specific PCR(KASP)marker developed based on the mutation site of the underlying gene would be helpful for pepper breeding.
基金financially supported by the grants from the earmarked fund for Xinjiang Agriculture Research System,China(XJARS-06)the Key Research and Development Task Special Project of Xinjiang,China(2022B02002-3)+1 种基金the Tianshan Talent Training Program,China(2023TSYCLJ0015)the Key Research and Development Program of Xinjiang Uygur Autonomous Region,China(2023B02017).
文摘Melon is a globally cultivated horticultural crop with a predominantly hybrid commercial seed market in China.Seedling morphology,particularly hypocotyl color,is a valuable trait for rapid F1 hybrid seed purity assessment.While green hypocotyls are common,white hypocotyls are rare in melon germplasm.This study identified a mutant with white hypocotyl but green leaves from the heavy ion beam mutant library.Genetic analysis revealed that a single recessive gene controlled the white hypocotyl,designated CmGhc1.A single-base deletion in the fifth exon of CmGhc1 led to a truncated CmGhc1 lacking the HTH-MYB DNA binding domain,likely affecting its transcriptional activity.CmGhc1 was localized in the nucleus,and yeast two-hybrid analysis and a dual-LUC assay demonstrated it as a transcription repressor.Furthermore,a KASP marker(hc1)was developed and verified as a functional marker for breeding white hypocotyl germplasms in melon.RNA-seq data revealed that CmGhc1 significantly affected the transcription of genes related to chlorophyll metabolism and photosynthesis in hypocotyl.In summary,these findings contribute to our understanding of chloroplast biogenesis and provide a valuable tool for melon breeding.
基金supported by grants from the Key R and D Program of Zhejiang(Grant Nos.2022C02032 and 2022C02030)the SanNong JiuFang Science and Technology Cooperation Project of Zhejiang Province(Grant No.2023SNJF008)+1 种基金the Grand Science and Technology Special Project of Zhejiang Province(Grant No.2021C02065)the Science and Technology Plan Project of Jiaxing(Grant No.2023AZ11002).
文摘Hypocotyl length is regarded to be a crucial seedling trait,influencing many subsequent plant development processes.However,little is known about this trait in Brassica campestris syn.Brasscia rapa.Here,we performed a comparative observation on the early hypocotyl development between two cultivars,‘SZQ’belonging to pak-choi(B.campestris ssp.chinensis var.communis)with longer hypocotyls,and‘WTC’belonging to Tacai(B.campestris L.ssp.chinensis var.rosularis)with shortter hypocotyls,and found that the difference in auxin biosynthesis might contribute to the varied hypocotyl phenotype between these two cultivars.By applying GWAS analysis using a total of 226 B.campestris accessions,we identified that the AT-Hook motif nuclear localized(AHL)gene BcAHL24-MF1 contributed to the natural variation in hypocotyl length.Functional variation of BcAHL24-MF1 was attributed to four haplotypes featuring four SNPs within the promoter region,of which Hap I accumulated more transcripts with shorter hypocotyls.Constitutive overexpression of BcAHL24-MF1 in B.campestris caused decreased hypocotyl length under light circumstances and even constant darkness,as BcAHL24-MF1 repressed the PIFmediated transcriptional activation of auxin biosynthesis genes BcYUC6-MF2 and BcYUC8-LF.Our research uncovered the important role of BcAHL24-MF1 in regulating light-triggered inhibition of hypocotyl elongation,therefore presenting a valuable genetic target for crop breeding.
文摘The plasma membrane vesicles were purified from soybean (Glycine max L.) hypocotyls by two_phase partitioning methods. The stimulatory effects of K + on the coupling between ATP hydrolysis and proton transport by the plasma membrane H +_ATPase were studied. The results showed that the proton transport activity was increased by 850% in the presence of 100 mmol/L KCl, while ATP hydrolytic activity was only increased by 28.2%. Kinetic studies showed that K m of ATP hydrolysis decreased from 1.14 to 0.7 mmol/L, while V max of ATP hydrolysis increased from 285.7 to 344.8 nmol Pi·mg -1 protein·min -1 in the presence of KCl. Experiments showed that the optimum pH was 6.5 and 6.0 in the presence and absence of KCl, respectively. Further studies revealed that K + could promote the inhibitory effects of hydroxylamines and vanadates on the ATP hydrolytic activity. The above results suggested that K + could regulate the coupling between ATP hydrolysis and proton transport of the plasma membrane H +_ATPase through modulating the structure and function of the kinase and phosphatase domains of the plasma membrane H +_ATPase.
文摘The stimulatory effect of lysophosphatidylcholine (lyso_PC) on ATP and ρ_nitrophenyl phosphate (PNPP) hydrolysis by the plasma membrane H +_ATPase from soybean (Glycine max (L.) Merr.) hypocotyls was studied. Results showed that lyso_PC stimulated the hydrolysis of ATP; ATP hydrolysis was enhanced dramatically when lyso_PC was within 0-0.03%, and increased slightly when lyso_PC was higher than 0.03%. At the concentration of 0.03%, lyso_PC stimulated ATP hydrolysis by 80.5%. Kinetics analysis showed that V max increased from 0.46 μmol P i·mg -1 protein·min -1 to 0.87 μmol P i·mg -1 protein·min -1 while K m increased from 0.88 mmol/L to 1.15 mmol/L under lyso_PC treatment. The optimum pH of ATP hydrolysis was shifted from 6.5 to 7.0 . Moreover, it was found lyso_PC enhanced the inhibition of ATP hydrolysis by hydroxylamine. In the presence of 200 mmol/L hydroxylamine, ATP hydrolysis was inhibited by 74.4%, while it was inhibited by 84.4% when treated with lyso_PC. However, PNPP hydrolysis and the inhibitory effect of vanadate were not affected by lyso_PC. The above results indicated that the kinase domain might be an action site or regulatory region of the C_terminal autoinhibitory domain in the plant plasma membrane H +_ATPase.
基金Supported by Science and Technology Development Program of Jilin Province(20110909)Youth Foud of Baicheng Normal University(200801)~~
文摘[Objective] This study aimed to investigate rapid multiplication of Apocynum by tissue culture so as to provide plantlet sources for its industrialized cultivation. [Method] The asepsis seedlings were obtained by dealing with Apocynum seeds. Its cotyledons, hypocotyls and shoot tips were cultured on the media containing different concentrations of hormones. Finally, the influence of different hormone combinations on differentiation of cotyledons and hypocotyls, rapid multiplication of shoot tips, rapid multiplication of regenerated shoots, and rooting of test-tube plantlets was com- pared. [Result] MS＋2.0 mg/L BA＋0.03 mg/L NAA and MS＋0.07 mg/L NAA were the optimum medium for inducing regenerated buds from cotyledons and hypocotyls re- spectively; MS＋2.0 mg/L BA＋0.02 mg/L NAA was the best medium for rapid multi- plication of shoot tips; MS＋1.9 mg/L BA＋I.7 mg/L NAA was the best medium for rapid multiplication of regenerated buds： and 1/2MS＋0.6 mg/L NAA was the best medium for inducing roots. [Conclusion] The optimum hormone combination was de- termined for Apocynum rapid multiplication by tissue culture, which provides technical support on Apocynum industrialized cultivation.
基金supported by the National Natural Science Foundation of China (31260336 and 31460353)
文摘An efficient plant regeneration protocol was established for castor bean （Ricinus communis L.）, in which 0.3 mg L-1 thidiazuron （TDZ） induced shoot clusters and increased the number of adventitious shoots from hypocotyl tissue. Our results showed that treatment under dark conditions significantly promoted the average number of shoots per explant to 37.36±4.54 （with a 6-d treatment）. Modified 1/2 Murashige and Skoog （MS） basal medium supplemented with 440 mg L-1 Ca2＋, 0.2 mg L-1 gibberellic acid and 0.1 mg L-1 TDZ significantly increased shoot elongation rates and lowered vitrification rates. Further- more, 1/2 MS media supplemented with 0.2 mg L-11-naphthaleneacetic acid induced a higher rooting rate compared with other culture conditions.
基金funded by the National Natural Science Foundation of China(Grant No.31970289).
文摘Ambient temperature induces the hypocotyl elongation of seedling,called as thermomorphogenesis.It has been reported that the bHLH transcriptional factor PIF7 acts as the critical component to modulate plant thermomorphogenesis,but the underlying mechanism remains elusive.The phytohormone abscisic acid(ABA)suppresses the hypocotyl elongation under high temperature(HT)stress.As the ABI5 binding protein,AFP2 acts as the negative factor to control ABA signaling.In this study,we first identified AFP2 as the interaction protein of PIF7 in vitro and in vivo.Phenotype analysis revealed that overexpressing AFP2 reduced the hypocotyl elongation,while loss-of-function afp2 mutant showed longer hypocotyl under HT.Consistently,overexpressing AFP2 impaired the transactivation effect of PIF7 on auxin biosynthesis related genes YUC8 and IAA19,which possibly resulted into the shorter hypocotyl in the transgenic line overexpressing AFP2 or co-overexpressing AFP2 and PIF7.Thus,these data suggest that AFP2 suppressed PIF7 activity to suppress hypocotyl elongation.Furthermore,we found that HT gradually induced the degradation of AFP2 that possibly released the inhibitory effect of AFP2 on PIF7,thus induced hypocotyl elongation under HT.Taken together,our result reveals the novel function of AFP2 in coordinating thermomorphogenesis through sophistically modulating PIF7 activity.
基金Supported by Key Joint Foundation for Fostering Talents of NSFC-Henan Province(U1204307)Key Project of Science and Technology of Henan Province(102102110155,142102110173,152102210334)Cultivation Fund of Luoyang Normal University(2013-PYJJ-001,10000993)
文摘Seeds of soybeans and mung beans were soaked into five different concentrations （0, 0.05, 0.10, 0.20, 0.30 mg/L） of natural brassinolide （ NBR ） solution. According to the results, natural brassinolide treatment could improve seed germination rate and hypocotyl-radicle ratio of soybeans and mung beans and promote the growth of sprouts. To be specific, seed germination rate of soybeans reached the highest in 0.05 mg/L natural brassinolide treatment, which was im- proved by 25.0 percentage points compared with the control group, and the sprout length was improved by 4.33 em; 0.30 mg/L natural brassinolide exhibited the most significant promotion effect on seed germination and sprout growth of mung beans, seed germination rate was improved by 18.3 percentage points and sprout length was improved by 7.29 cm; hypocotyl-radiele ratio of soybean and mung bean sprouts reached the highest （2.96, 1.43 ） in 0.05 mg/L natural brassinolide treatment.
文摘The germination capacity of Ailanthus altissima seeds improved after the seeds were soaked with different concentrations of natural brassinolide （NBR）. The germination rate and germination energy of the seeds increased by 17.6% and 18.8%, and the mean germination speed （i.e., germination time） of the seeds was shortened by 1.4 d under the optimal concentration （0.4 mg·L^-1） treatment, compared with the control. After hypocotyls of A.altissima were treated with NBR, the elongation of the hypocotyls increased. Among different concentrations of the NBR, 0.4 mg·L^-1 NBR appeared to be the optimal concentration for the elongation of A.altissima hypocotyls.
基金supported by a grant from the Chinese National Natural Science Foundation(Nos.30270682 and 30770211)to X.Wangsupported in part by a Monsanto Fellowship to the Peking-Yale Joint Center,USA
文摘The COP9 signalosome （CSN） is a multiprotein complex which participates in diverse cellular and developmental processes. CSN1, one of the subunits of CSN, is essential for assembly of the multiprotein complex via PCI （proteasome, COP9 signalosome and initiation factor 3） domain in the C-terminal half of CSN 1. However, the role of the N-terminal domain （NTD） of CSN 1, which is critical for the function of CSN, is not completely understood. Using a yeast two-hybrid （Y2H） screen, we found that the NTD of CSN1 interacts with TSK-associating protein 1 （TSA1）, a reported CaZ＋-binding protein. The interaction between CSN1 and TSA1 was confirmed by co-immunoprecipitation in Arabidopsis. tsal mutants exhibited a short hypocotyl phenotype in darkness but were similar to wild-type Arabidopsis under white light, which suggested that TSA1 might regulate Arabidopsis hypocotyl development in the dark. Furthermore, the expression of TSA1 was significantly lower in a csnl null mutant （fus6）, while CSN1 expression did not change in a tsal mutant with weak TSAI expression. Together, these findings suggest a functional relationship between TSAI and CSN1 in seedling development.
文摘We studied the roles of different concentrations of gibberellin A_(3)(GA_(3))in breaking hypocotyl dormancy of Paeonia anomala subsp.veitchii,aiming to provide a theoretical basis for the efficient elimination of seed dormancy.The seeds of P.anomala subsp.veitchii were treated with different concentrations of GA_(3)(0,100,200,300,and 400 mg/L)under dark conditions at 16℃,and then the rooting indicators including rooting rate,rooting vigor,rooting index and mold rot rate were determined.The treatment with 400 mg/L GA_(3) for 4 h showed the best performance in breaking the hypocotyl dormancy.Specifically,the treatment shortened the rooting time to 12 d,increased the rooting rate,rooting vigor,and rooting index to 84.00%±5.29%,80.67%±5.03%,and 2.25±0.16 respectively,and decreased the mold rot rate to 0.67%±1.16%.To sum up,there were germination inhibitors in the seeds of P.anomala subsp.veitchii,while the addition of exogenous hormone GA_(3) can release the inhibitory effect on the hypocotyl,which indicated that GA_(3) can promote the breaking of hypocotyl dormancy.
基金supported by the National Natural Science Foundation of China(32001578)Qingdao Science&Technology Key Projects(22-1-3-1-zyyd-nsh,23-1-3-8-zyyd-nsh)+1 种基金Salt-Alkali Agriculture Industry System of Shandong Province(SDAIT-29-03)Science&Technology Specific Projects in Agricultural High-tech Industrial Demonstration Area of the Yellow River Delta(2022SZX19)。
文摘Ethylene plays essential roles in plant growth,development and stress responses.The ethylene signaling pathway and molecular mechanism have been studied extensively in Arabidopsis and rice but limited in peanuts.Here,we established a sand-culture method to screen pingyangmycin mutagenized peanut lines based on their specific response to ethylene(“triple response”).An ethylene-insensitive mutant,inhibition of peanut hypocotyl elongation 1(iph1),was identified that showed reduced sensitivity to ethylene in both hypocotyl elongation and root growth.Through bulked segregant analysis sequencing,a major gene related to iph1,named AhIPH1,was preliminarily mapped at the chromosome Arahy.01,and further narrowed to a 450-kb genomic region through substitution mapping strategy.A total of 7014 genes were differentially expressed among the ACC treatment through RNA-seq analysis,of which only the Arahy.5BLU0Q gene in the candidate mapping interval was differentially expressed between WT and mutant iph1.Integrating sequence variations,functional annotation and transcriptome analysis revealed that a predicated gene,Arahy.5BLU0Q,encoding SNF1 protein kinase,may be the candidate gene for AhIPH1.This gene contained two single-nucleotide polymorphisms at promoter region and was more highly expressed in iph1 than WT.Our findings reveal a novel ethylene-responsive gene,which provides a theoretical foundation and new genetic resources for the mechanism of ethylene signaling in peanuts.
文摘Adventitious shoots were successfully regenerated from hypocotyl explants of in vitro cultures of Euonymus japonicus Cu zhi. Hypocotyl slices were cultured on Murashige and Skoog （MS） and B5 basal medium supplemented with varied concentration of different plant growth-regulators, e.g., α-naphthaleneacetic acid （NAA） and indole-3-butyric acid （IBA） in combination with 6-benzylaminopurine （6-BA） and kinetin. The study showed that shoots could be directly regenerated from hypocotyl explants without the intervening callus phase; MS medium was more suitable for adventitious shoots regeneration. The ability of hypocotyls segments to produce shoots varied depending upon their position on the seedlings. The highest regeneration rate was obtained with hypocotyl segments near to the cotyledon cultured on MS basal medium supplemented with 1.5 mg L^-1 6-BA and 0.05 mg L^-1 NAA （63.64%）. The regenerated shoots were readily elongated on the same medium as used for multiplication and rooted on half-strength MS basal medium supplemented with 1.0 mg L^-1 IBA and 100 mg L^-1 activated carbon. After being transferred to greenhouse conditions, 96% of the plantlets were successfully acclimatized. This regeneration system is applied for genetic transformation now.
文摘The influence of humic substances (HS) formulations derived from sedimentary and compost sources was studied on plant growth at cell level and chlorophyll retention during accelerated senescence of leaf tissue. The direct effect of HS formulations was studied on cell expansion using cucumber and radish cotyledon expansion test. The cucumber hypocotyl elongation test was used to study the effect on cell elongation. Chlorophyll pigment retention in excised leaf tissue incubated in dark with high temperature was assessed to study the effect on leaf senescence. Explant tissues were incubated directly in the solutions of the formulations at the concentration recommended for foliar application to the crop plants. HS formulations showed significant variations in their direct bio-stimulatory effects. Formulations derived from compost sources were found superior in terms of inducing a direct stimulatory effect on cell expansion and cell elongation and in maintaining chlorophyll pigment retention during accelerated senescence. HS from sedimentary sources stimulated cell expansion and delayed chlorophyll degradation to a lesser extent compared to HS from compost. However, HS formulations derived from sedimentary sources used in this study were not effective in inducing cell elongation in the cucumber hypocotyl elongation test. The direct bio-stimulatory effect of HS formulations differed significantly between the formulations that were evaluated.
基金The financial assistance for conducting this study was provided by Maulana Azad National Fellowship-SRF(Award number MANF-2013-14-MUS–BIH-21399),UGC,IndiaFor the purchase of chemicals,provided by projects with Vide numbers SB/YS/LS-156/2013 and SB/FT/LS-364/2012
文摘Santalum album L.is a commercially important tree that yields essential oil of high medicinal value.Regeneration research through organogenesis and embryogenesis has been documented but no report depicts comparative ontogeny of directly differentiating shoot buds(SB)and somatic embryos(SE).In the present study aseptic seedling derived hypocotyl segments(HC)and hypocotyl+root junction(HC+R)were used to induce SBs and SEs,respectively.Ontogenic differences between the structures were confirmed using scanning electron microscopy and histological analysis.MS medium containing 6-benzyladenine or BA(2.5μM)produced highest number of direct SB,while MS+BA(7.5μM)proved suitable for higher frequency of SE differentiation.The differentiating structures attained growth when transferred to MS medium containing a combination of BA and anaphthalene acetic acid or silver nitrate(AgNO3).A combination of indole-3-butyric acid and silver nitrate(AgNO3)in half-strength woody plant medium and lesser osmotic concentration(2%sucrose),induced rhizogenesis.
基金Supported by the China Manned Space Flight Technology Project TG-2the National Natural Science Foundation of China(31670864)+2 种基金the National Natural Fund Joint Fund Project(U1738106)the Strategic Pioneer Projects of CAS(XDA15013900)the National Science Foundation for Young Scientists of China(31500687)
文摘Gravitropic curvature growth of Arabidopsis hypocotyls mainly occurred in the rapid growing Elongation Zone(EZI),not in the slow-growing Elongation Zone(EZII).By examining reorientation of Microtubules(MT)and phenotype of the cell wall in the EZI and the EZII of Arabidopsis hypocotyls under normal gravitational condition,it is found that MTs in the rapid growing epidermal cells were mainly in the transverse direction,while those in the non-growing epidermal cells were in the longitudinal directions.However,this difference in cortical MT arrays between the EZI and EZII cells disappeared when the seedlings were exposed to the simulated microgravity condition on a horizontal clinostat.Field emission scanning electron microscopy revealed that the surface texture of epidermal cells,like the direction of the MT,in the EZI and the EZII also became similar when exposed to the simulated microgravity condition.This result indicated that simulate microgravity could modify the potential differentiation between the EZI and the EZII by affecting the orientation of cortical MT in the epidermal cells.
