Cold stress is an important factor that limits apple production. In this study, we examined the tissue-cultured plantlets of apple rootstocks ‘M9T337' and ‘60-160', which are resistant and sensitive to cold ...Cold stress is an important factor that limits apple production. In this study, we examined the tissue-cultured plantlets of apple rootstocks ‘M9T337' and ‘60-160', which are resistant and sensitive to cold stress, respectively. The enriched pathways of differentially expressed genes(DEGs) and physiological changes in ‘M9T337' and ‘60-160' plantlets were clearly different after cold stress(1°C) treatment for 48 h, suggesting that they have differential responses to cold stress. The differential expression of WRKY transcription factors in the two plantlets showed that MdWRKY40is and MdWRKY48 are potential regulators of cold tolerance. When we overexpressed MdWRKY40is and MdWRKY48in apple calli, the overexpression of MdWRKY48 had no significant effect on the callus, while MdWRKY40is overexpression promoted anthocyanin accumulation, increased callus cold tolerance, and promoted the expression of anthocyanin structural gene MdDFR and cold-signaling core gene MdCBF2. Yeast one-hybrid screening and electrophoretic mobility shift assays showed that MdWRKY40is could only bind to the MdDFR promoter. Yeast twohybrid screening and bimolecular fluorescence complementation showed that MdWRKY40is interacts with the CBF2inhibitor MdMYB15L through the leucine zipper(LZ). When the LZ of MdWRMY40is was knocked out, MdWRKY40is overexpression in the callus did not affect MdCBF2 expression or callus cold tolerance, indicating that MdWRKY40is acts in the cold signaling pathway by interacting with MdMYB15L. In summary, MdWRKY40is can directly bind to the MdDFR promoter in order to promote anthocyanin accumulation, and it can also interact with MdMYB15L to interfere with its inhibitory effect on MdCBF2, indirectly promoting MdCBF2 expression, and thereby improving cold tolerance.These results provide a new perspective for the cold-resistance mechanism of apple rootstocks and a molecular basis for the screening of cold-resistant rootstocks.展开更多
Acer rubrum is an important garden color-leafed plant.Its leaves will turn red in autumn,which is of great orna-mental value.The leaf color change in Acer rubrum is closely associated with anthocyanins accumulation.In...Acer rubrum is an important garden color-leafed plant.Its leaves will turn red in autumn,which is of great orna-mental value.The leaf color change in Acer rubrum is closely associated with anthocyanins accumulation.In anthocyanin synthesis and accumulation,various transcription factor families play significant regulatory roles,including the basic(region)leucine zipper(bZIP).However,there is no report on the systematic identification and functional analysis of the bZIPs in Acer rubrum.In this study,137 bZIPs distributed on 29 chromosomes of Acer rubrum were identified and renamed according to their locations on the chromosomes.According to the constructed bZIP phylogenetic tree of Arabidopsis thaliana and Acer rubrum,bZIPs were divided into 13 groups.Two pairs of bZIP genes were involved in tandem duplication,and 106 segmental duplication gene pairs were found.Cis-acting elements in the promoter region of these bZIP genes were analyzed.The results of promoter analysis showed that many elements were closely related to light conditions,hormone responses,and abiotic stress factors.Among them,the cis-acting elements related to light response were most abundant and prominent.The results of anthocyanin determination showed that anthocyanin contents in the leaves of Acer rubrum increased significantly under low temperature with light.In addition,gene expression analysis showed that compared to other ArbZIPs,ArbZIP137,ArbZIP136,ArbZIP114,ArbZIP130,and ArbZIP14 showed a more pronounced increase in gene expression both under low-temperature conditions and under light conditions.From the correlation analysis,there was a high correlation between ArbZIPs and several anthocyanin-regulated transcription factors,including ArMYBs,ArbHLH and ArWD40s.Conclusively,the bZIP genes in Acer rubrum were identified and analyzed,providing a foundational basis for future studies on their function and significantly enhancing our understanding of the color mechanism of Acer rubrum.展开更多
Variation laws of anthocyanin content in root during the development and among the varieties, and their relationships with major economic traits in purple-fleshed sweetpotato [Ipomoea batatas （L.） Lam] were studied ...Variation laws of anthocyanin content in root during the development and among the varieties, and their relationships with major economic traits in purple-fleshed sweetpotato [Ipomoea batatas （L.） Lam] were studied in the present article. The dynamics of 20 economic traits in 13 purple-fleshed sweetpotato varieties at 20, 40, 60, 80, 100, 120, and 140 d after their transplanting were investigated, and these traits included anthocyanin content in root, length of the longest vine, number of base branches, root number, dry matter contents in stem, foliage and root, fresh/dry weight of root, fresh/dry weight of stem, flesh/dry weight of foliage, flesh/dry weight of stem and foliage, flesh/dry weight of whole plant, and rations of photosynthate to root, stem, and foliage. The correlations between the variations of anthocyanin content and the other 19 economic traits among varieties and during the whole developing stages, and the correlations of daily increase of anthocyanin content with other l0 kinds of yields were analyzed. The results showed that： （1） During the whole development, the anthocyanin content had three variation types, i.e. a slow-increase type, a fluctuating-change type, and a deviousrising type, and had different responses to the growth of length of the longest vine, number of base branches, flesh/dry yield of root, and photosynthate allotments. （2） The anthocyanin contents among 13 varieties began to have significant difference after 20 d, and showed completed differentiation during 40-100 d, which had significantly negative correlationships with the number of base branches, fresh/dry yield of root, photosynthate allotment ratio to root, and had significant positive correlationships with dry matter content of root, length of the longest vine, fresh/dry yield of stem, dry yield of whole plant and photosynthate allotment ratio to foliage. （3） Because of the significantly negative correlation between daily increase of anthocyanin content and dry matter weight of root, the anthocyanin accumulation competed with dry matter accumulation for photosynthate in root, and the competitive relation was resolved in different ways in different purple-fleshed sweetpotato （PFSP） varieties. So, there had three variation types of anthocyanin content among PFSP varieties during their development, and had different correlations between these variations of anthocyanin content and the major economic traits.展开更多
The embryo spot trait leads to a deep purple or reddish coloration at the base of the cotyledons of the embryo,visible on both sides of flat potato(Solanum tuberosum)seeds.This trait has long been used by potato resea...The embryo spot trait leads to a deep purple or reddish coloration at the base of the cotyledons of the embryo,visible on both sides of flat potato(Solanum tuberosum)seeds.This trait has long been used by potato researchers and breeders as a morphological marker during dihaploid induction.The formation of embryo spots reflects the accumulation of anthocyanins,but the genetic basis of this trait remains unclear.In this study,we mapped the embryo spot trait to a 6.78-Mb region at the end of chromosome 10 using an F2 population derived from a cross between spotted and spotless plants.The recombination rate in the candidate region is severely suppressed,posing challenges for the map-based cloning of the underlying gene and suggesting large-scale rearrangements in this region.A de novo genome assembly of the spotted individual and a comparative genomic analysis to the reference genome of spotless potato revealed a 6.49-Mb inversion present in the spotted plant genome.The left breakpoint of this inversion occurred in the promoter region of an R2R3 MYB transcription factor gene that is highly expressed in the cotyledon base of spotted embryos but is not expressed in that of spotless embryos.This study elucidated the genetic basis for embryo spot formation in potato and provides a foundation for future cloning of the causative gene.展开更多
The phytohormone jasmonate(JA)coordinates stress and growth responses to increase plant survival in unfavorable environments.Although JA can enhance plant UV-B stress tolerance,the mechanisms underlying the interactio...The phytohormone jasmonate(JA)coordinates stress and growth responses to increase plant survival in unfavorable environments.Although JA can enhance plant UV-B stress tolerance,the mechanisms underlying the interaction of UV-B and JA in this response remain unknown.In this study,we demonstrate that the UV RESISTANCE LOCUS 8-TEOSINTE BRANCHED1,Cycloidea and PCF 4-LIPOXYGENASE2(UVR8-TCP4-LOX2)module regulates UV-B tolerance dependent on JA signaling pathway in Arabidopsis thaliana.We show that the nucleus-localized UVR8 physically interacts with TCP4 to increase the DNA-binding activity of TCP4 and upregulate the JA biosynthesis gene LOX2.Furthermore,UVR8 activates the expression of LOX2 in a TCP4-dependent manner.Our genetic analysis also provides evidence that TCP4 acts downstream of UVR8 and upstream of LOX2 to mediate plant responses to UV-B stress.Our results illustrate that the UV-B-dependent interaction of UVR8 and TCP4 serves as an important UVR8-TCP4-LOX2 module,which integrates UV-B radiation and JA signaling and represents a new UVR8 signaling mechanism in plants.展开更多
基金supported by the Natural Science Foundation of Shandong Province, China (ZR2021MC045)the Key Research & Development Plan (Major Scientific and Technological Innovation Project) of Shandong Province, China (2021LZGC024)the earmarked fund for China Agriculture Research System(CARS-27)。
文摘Cold stress is an important factor that limits apple production. In this study, we examined the tissue-cultured plantlets of apple rootstocks ‘M9T337' and ‘60-160', which are resistant and sensitive to cold stress, respectively. The enriched pathways of differentially expressed genes(DEGs) and physiological changes in ‘M9T337' and ‘60-160' plantlets were clearly different after cold stress(1°C) treatment for 48 h, suggesting that they have differential responses to cold stress. The differential expression of WRKY transcription factors in the two plantlets showed that MdWRKY40is and MdWRKY48 are potential regulators of cold tolerance. When we overexpressed MdWRKY40is and MdWRKY48in apple calli, the overexpression of MdWRKY48 had no significant effect on the callus, while MdWRKY40is overexpression promoted anthocyanin accumulation, increased callus cold tolerance, and promoted the expression of anthocyanin structural gene MdDFR and cold-signaling core gene MdCBF2. Yeast one-hybrid screening and electrophoretic mobility shift assays showed that MdWRKY40is could only bind to the MdDFR promoter. Yeast twohybrid screening and bimolecular fluorescence complementation showed that MdWRKY40is interacts with the CBF2inhibitor MdMYB15L through the leucine zipper(LZ). When the LZ of MdWRMY40is was knocked out, MdWRKY40is overexpression in the callus did not affect MdCBF2 expression or callus cold tolerance, indicating that MdWRKY40is acts in the cold signaling pathway by interacting with MdMYB15L. In summary, MdWRKY40is can directly bind to the MdDFR promoter in order to promote anthocyanin accumulation, and it can also interact with MdMYB15L to interfere with its inhibitory effect on MdCBF2, indirectly promoting MdCBF2 expression, and thereby improving cold tolerance.These results provide a new perspective for the cold-resistance mechanism of apple rootstocks and a molecular basis for the screening of cold-resistant rootstocks.
基金This study was funded by the National Natural Science Foundation of China(Project No.32271914)the Natural Science Foundation of Anhui Province(2108085MC110).
文摘Acer rubrum is an important garden color-leafed plant.Its leaves will turn red in autumn,which is of great orna-mental value.The leaf color change in Acer rubrum is closely associated with anthocyanins accumulation.In anthocyanin synthesis and accumulation,various transcription factor families play significant regulatory roles,including the basic(region)leucine zipper(bZIP).However,there is no report on the systematic identification and functional analysis of the bZIPs in Acer rubrum.In this study,137 bZIPs distributed on 29 chromosomes of Acer rubrum were identified and renamed according to their locations on the chromosomes.According to the constructed bZIP phylogenetic tree of Arabidopsis thaliana and Acer rubrum,bZIPs were divided into 13 groups.Two pairs of bZIP genes were involved in tandem duplication,and 106 segmental duplication gene pairs were found.Cis-acting elements in the promoter region of these bZIP genes were analyzed.The results of promoter analysis showed that many elements were closely related to light conditions,hormone responses,and abiotic stress factors.Among them,the cis-acting elements related to light response were most abundant and prominent.The results of anthocyanin determination showed that anthocyanin contents in the leaves of Acer rubrum increased significantly under low temperature with light.In addition,gene expression analysis showed that compared to other ArbZIPs,ArbZIP137,ArbZIP136,ArbZIP114,ArbZIP130,and ArbZIP14 showed a more pronounced increase in gene expression both under low-temperature conditions and under light conditions.From the correlation analysis,there was a high correlation between ArbZIPs and several anthocyanin-regulated transcription factors,including ArMYBs,ArbHLH and ArWD40s.Conclusively,the bZIP genes in Acer rubrum were identified and analyzed,providing a foundational basis for future studies on their function and significantly enhancing our understanding of the color mechanism of Acer rubrum.
基金the Natural Science Foundation of Chongqing Science and Technology Commission,China(CSTC2005BB1105)National Key Technology R&D Program of China(2006BAD01A06-2-06)Animal and Crop Fine Variety Innovation Program of Chongqing City,China(10379).
文摘Variation laws of anthocyanin content in root during the development and among the varieties, and their relationships with major economic traits in purple-fleshed sweetpotato [Ipomoea batatas （L.） Lam] were studied in the present article. The dynamics of 20 economic traits in 13 purple-fleshed sweetpotato varieties at 20, 40, 60, 80, 100, 120, and 140 d after their transplanting were investigated, and these traits included anthocyanin content in root, length of the longest vine, number of base branches, root number, dry matter contents in stem, foliage and root, fresh/dry weight of root, fresh/dry weight of stem, flesh/dry weight of foliage, flesh/dry weight of stem and foliage, flesh/dry weight of whole plant, and rations of photosynthate to root, stem, and foliage. The correlations between the variations of anthocyanin content and the other 19 economic traits among varieties and during the whole developing stages, and the correlations of daily increase of anthocyanin content with other l0 kinds of yields were analyzed. The results showed that： （1） During the whole development, the anthocyanin content had three variation types, i.e. a slow-increase type, a fluctuating-change type, and a deviousrising type, and had different responses to the growth of length of the longest vine, number of base branches, flesh/dry yield of root, and photosynthate allotments. （2） The anthocyanin contents among 13 varieties began to have significant difference after 20 d, and showed completed differentiation during 40-100 d, which had significantly negative correlationships with the number of base branches, fresh/dry yield of root, photosynthate allotment ratio to root, and had significant positive correlationships with dry matter content of root, length of the longest vine, fresh/dry yield of stem, dry yield of whole plant and photosynthate allotment ratio to foliage. （3） Because of the significantly negative correlation between daily increase of anthocyanin content and dry matter weight of root, the anthocyanin accumulation competed with dry matter accumulation for photosynthate in root, and the competitive relation was resolved in different ways in different purple-fleshed sweetpotato （PFSP） varieties. So, there had three variation types of anthocyanin content among PFSP varieties during their development, and had different correlations between these variations of anthocyanin content and the major economic traits.
基金supported by the China National Key Research and Development Program(Grant No.2019YFE0120500 to CZ)the National Natural Science Foundation of China(32372695)+3 种基金the Agricultural Science and Technology Innovation Program(CAASZDRW202101)the China Postdoctoral Science Foundation(2021M693456)the Central government guidance for local scientific and technological development projects(23ZYQJ304)the Agricultural Science and Technology Innovation Program(CAAS-ZDRW202404).
文摘The embryo spot trait leads to a deep purple or reddish coloration at the base of the cotyledons of the embryo,visible on both sides of flat potato(Solanum tuberosum)seeds.This trait has long been used by potato researchers and breeders as a morphological marker during dihaploid induction.The formation of embryo spots reflects the accumulation of anthocyanins,but the genetic basis of this trait remains unclear.In this study,we mapped the embryo spot trait to a 6.78-Mb region at the end of chromosome 10 using an F2 population derived from a cross between spotted and spotless plants.The recombination rate in the candidate region is severely suppressed,posing challenges for the map-based cloning of the underlying gene and suggesting large-scale rearrangements in this region.A de novo genome assembly of the spotted individual and a comparative genomic analysis to the reference genome of spotless potato revealed a 6.49-Mb inversion present in the spotted plant genome.The left breakpoint of this inversion occurred in the promoter region of an R2R3 MYB transcription factor gene that is highly expressed in the cotyledon base of spotted embryos but is not expressed in that of spotless embryos.This study elucidated the genetic basis for embryo spot formation in potato and provides a foundation for future cloning of the causative gene.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2019QZKK0502)the National Natural Science Foundation of China(No.32370405).
文摘The phytohormone jasmonate(JA)coordinates stress and growth responses to increase plant survival in unfavorable environments.Although JA can enhance plant UV-B stress tolerance,the mechanisms underlying the interaction of UV-B and JA in this response remain unknown.In this study,we demonstrate that the UV RESISTANCE LOCUS 8-TEOSINTE BRANCHED1,Cycloidea and PCF 4-LIPOXYGENASE2(UVR8-TCP4-LOX2)module regulates UV-B tolerance dependent on JA signaling pathway in Arabidopsis thaliana.We show that the nucleus-localized UVR8 physically interacts with TCP4 to increase the DNA-binding activity of TCP4 and upregulate the JA biosynthesis gene LOX2.Furthermore,UVR8 activates the expression of LOX2 in a TCP4-dependent manner.Our genetic analysis also provides evidence that TCP4 acts downstream of UVR8 and upstream of LOX2 to mediate plant responses to UV-B stress.Our results illustrate that the UV-B-dependent interaction of UVR8 and TCP4 serves as an important UVR8-TCP4-LOX2 module,which integrates UV-B radiation and JA signaling and represents a new UVR8 signaling mechanism in plants.
