Pseudomonas syringae pv.actinidiae(Psa)causes destructive kiwifruit bacterial canker by invading vascular tissues across multiple plant organs.However,the cellular mechanism underlying its systemic transmission and ce...Pseudomonas syringae pv.actinidiae(Psa)causes destructive kiwifruit bacterial canker by invading vascular tissues across multiple plant organs.However,the cellular mechanism underlying its systemic transmission and cell-to-cell movement within these specialized vascular conduits remains unclear.In this study,a Psa-GFP strain and various microscopic techniques were used to investigate the interaction between kiwifruit and Psa.Our results reveal that Psa strategically exploits host vascular conduits for systemic movement,with the xylem vessel being the predominant avenue.In the phloem,Psa exhibits adaptive alteration in bacterial shape to traverse sieve pores,facilitating its systemic spread along sieve tubes and inducing phloem necrosis.Within the xylem,Psa breaches pit membranes to migrate between adjacent vessels.Furthermore,phloem fibers act as an initial barrier at the early stages of infection,delaying Psa's entry into vascular tissues during its journey to the xylem.Additionally,at the junctions of stem-stem or stem-leaf,branch trace or leaf trace mediates the bacterial organ-to-organ translocation,thus facilitating the systemic progression of disease.In conclusion,our findings shed light on the cellular mechanism employed by Psa to exploit the woody plant's vascular network for infection,thereby enhancing a better understanding of the biology of this poorly defined bacterium.These insights carry implications for the pathogenesis of Psa and other vascular pathogens,offering theoretical guidance for effective control strategies.展开更多
Pseudomonas syringae pv.actinidiae(Psa)causes bacterial canker,a devastating disease threatening the Actinidia fruit industry.In a search for non-host resistance genes against Psa,we find that the nucleotidebinding le...Pseudomonas syringae pv.actinidiae(Psa)causes bacterial canker,a devastating disease threatening the Actinidia fruit industry.In a search for non-host resistance genes against Psa,we find that the nucleotidebinding leucine-rich repeat receptor(NLR)protein ZAR1 from both Arabidopsis and Nicotiana benthamiana(Nb)recognizes Hop Z5 and triggers cell death.The recognition requires ZED1 in Arabidopsis and JIM2 in Nb plants,which are members of the ZRK pseudokinases and known components of the ZAR1 resistosome.Surprisingly,Arabidopsis ZAR1 and RPM1,another NLR known to recognize Hop Z5,confer disease resistance to Hop Z5 in a strain-specific manner.Thus,ZAR1,but not RPM1,is solely required for resistance to P.s.maculicola ES4326(Psm)carrying hop Z5,whereas RPM1 is primarily required for resistance to P.s.tomato DC3000(Pst)carrying hop Z5.Furthermore,the ZAR1-mediated resistance to Psm hop Z5 in Arabidopsis is insensitive to SOBER1,which encodes a deacetylase known to suppress the RPM1-mediated resistance to Pst hop Z5.In addition,hop Z5 enhances P.syringae virulence in the absence of ZAR1 or RPM1 and that SOBER1 abolishes such virulence function.Together the study suggests that ZAR1 may be used for improving Psa resistance in Actinidia and uncovers previously unknown complexity of effectortriggered immunity and effector-triggered virulence.展开更多
Objective Radix of Actinidiae chinensis,a medicinal plant used in China,is the dry root of Actini-diaceae plant and has been extensively employed to treat cancers of various organs,including the lung,liver and digesti...Objective Radix of Actinidiae chinensis,a medicinal plant used in China,is the dry root of Actini-diaceae plant and has been extensively employed to treat cancers of various organs,including the lung,liver and digestive system.However,up to now,its active antitumor and antiviral fractions remain unclear.The main purpose of this study is to identify the antitumor and antiviral sites of Radix of Actinidiae chinensis,which provides evidences for its further development.Methods Radix of Actinidiae chinensis was extracted by the refluxing sequentially with acetidin,ethanol and water,followed by the column chromatography and thin layer chromatography.The antitumor effects on Bel-7402,SW-620 and MDA-MB-231 tumor cells were investigated to screen the active antitumor sites by cell inhibition,the growth curve and the apoptosis staining.Meanwhile,to screen the active anti-hepatovirus fractions,the cell growth and the secretion of HBsAg and HBeAg in HepG2.2.15 cells were evaluated by the MTT test and enzyme-linked immunosorbent assay respectively.Results The acetidin fraction Y(Y1+Y2),the ethanol fraction A(A1+A3+A4) and B(A1+A4+A6),and the fraction compound C(A1+A4+Y1) have strong inhibitive effects on Bel-7402,SW-620 and MDA-MB-231 tumor cell lines.Moreover,the tumor cell apoptosis could be induced by the ethanol fraction B and the fraction compound C.In HepG2.2.15 cells,the treatment indexes of the acetidin fraction Y,the ethanol fraction A and the fraction compound C all exceeded 2 on the secretion of HBsAg,indicating the suppre-ssive effects of them on hepatitis B virus.The fraction yields of A,B and C exceeded 50%(60.28%,54.35% and 62.64% respectively),while that of Y did not(17.7%).Conclusion The ethanol fraction B and the fraction compound C are the antitumor sites of Actinidiae chinensis Radix,while the ethanol fraction A and the fraction compound C are its antiviral sites.展开更多
Ambient temperature affects the occurrence and prevalence of plant disease.Most bacterial diseases are damaging at high temperatures.However,kiwifruit bacterial canker caused by Pseudomonas syringae pv.actinidiae(Psa)...Ambient temperature affects the occurrence and prevalence of plant disease.Most bacterial diseases are damaging at high temperatures.However,kiwifruit bacterial canker caused by Pseudomonas syringae pv.actinidiae(Psa)has been found to be prevalent at relatively cool temperatures,and it is unclear how ambient temperature affects the development of kiwifruit bacterial canker.In this study,basal resistance to Psa was suppressed in kiwifruit at cool growth temperature(16℃)compared with at normal temperature(24℃).In addition,RNA sequence analysis and ethylene content assessment indicated that ethylene modulated kiwifruit resistance to Psa at normal growth temperature and that cool temperature inhibited ethylene accumulation and Psa-induced activation of the ethylene signaling pathway in kiwifruit.Virusmediated silencing of the kiwifruit ethylene signaling gene AcEIN2 suppressed kiwifruit resistance to Psa at normal growth temperature.Exogenous application of ethylene inhibitor 1-methylcyclopropene eliminated the difference in kiwifruit resistance to Psa at 16 and 24℃.Exogenous application of ethylene analogues ethephon induced resistance to Psa in kiwifruit.In conclusion,cool temperatures impair basal resistance to Psa by reducing the activation of ethylene biosynthesis and signaling in kiwifruit.The results provide clues for new strategies to control plant diseases in a context of global environmental change.展开更多
Waterlogging stress is one of the greatest environmental threats to kiwifruit growth and development.ERF-VII proteins have been demonstrated to play pivotal roles in regulating plant tolerance to waterlogging.Neverthe...Waterlogging stress is one of the greatest environmental threats to kiwifruit growth and development.ERF-VII proteins have been demonstrated to play pivotal roles in regulating plant tolerance to waterlogging.Nevertheless,the genome-wide role of ERF-VII in kiwifruit waterlogging stress tolerance remains unclear.Here,we report the function and regulatory network of an ERF-VII transcription factor located to the nucleus,Av ERF73,in kiwifruit waterlogging tolerance.Overexpression of Av ERF73 in Arabidopsis thaliana and A.chinensis cv.Hongyang enhanced waterlogging tolerance in transgenic plants.Furthermore,we performed transcriptome analysis(RNA-seq)and DNA affinity purification sequencing(DAP-seq)to explore the regulatory mechanism of Av ERF73.RNA-seq coupled with DAP-seq showed that Av ERF73 might directly activate Ac NAC022 involved in the“cellular response to hypoxia”process and Ac HMGS1 involved in the mevalonate pathway to respond to waterlogging,which were also confirmed by a dual-luciferase reporter assay.Based on our results,we propose a putative working model for controlling waterlogging tolerance by Av ERF73 in kiwifruit.展开更多
[Objective] The variation of sugar, acid and AsA contents in fruits of ‘Ganmi 6＇ kiwifruit （Actinidia eriantha Benth） were investigated during fruit develop- ment. [Method] Kiwi fruits were randomly taken as mater...[Objective] The variation of sugar, acid and AsA contents in fruits of ‘Ganmi 6＇ kiwifruit （Actinidia eriantha Benth） were investigated during fruit develop- ment. [Method] Kiwi fruits were randomly taken as materials every 15 days since 20 days after full bloom （DAFB） to 170 DAFB until in mature stage. [Result] The results showed that during fruit development of ‘Ganmi 6＇, the total sugar soluble contents had a rising trend with relatively stable at 95 DAFB, then rose until har- vest with the maximum content （10.35%）. The titratable acid content showed a trend of increasing, then declining, then increase to the harvest content （1.10%）. From the sugar acid ratio, we can knew it decreased in 95 DAFB, then up to the max （9.38）. The changes of AsA contents showed double ‘S＇ shape, decreased af- ter the first increased rapidly, slightly increased and then decreased in the early harvest. [Conclusion] It provided a theoretical basis for scientific cultivation methods to explore the nutrients regulation.展开更多
Protoplasts isolated from cotyledon-derived calli of Actinidia chinensis var. chinensis (2n = 2x=58) were fused by the PEG method with cotyledon-callus protoplasts of A. deliciosa var. deliciosa (2n = 6x = 174) or wit...Protoplasts isolated from cotyledon-derived calli of Actinidia chinensis var. chinensis (2n = 2x=58) were fused by the PEG method with cotyledon-callus protoplasts of A. deliciosa var. deliciosa (2n = 6x = 174) or with mesophyll protoplasts of A. kolomikta (2n = 2x = 58), respectively. Randomly amplified polymorphic DNA (RAPD) markers and flow cytometry was used to confirm the occurrence of somatic hybrids. RAPD results with some primers surveyed indicated that one clone (A. chinensis + A. deliciosa) and four clones (A. chinensis + A. kolomikta) had RAPD banding patterns which combined the parental banding profiles. Ploidy levels of the (A. chinensis + A. deliciosa) clone were deduced as octoploid (2n = 8x), and the (A. chinensis + A. kolomikta) clones were tetraploid (2n = 4x), triploid (2n = 3x) or pentaploid (2n = 5x). The clones were confirmed as interspecific somatic hybrids in Actinidia.展开更多
基金supported by grants from the National Key Research and Development Program of China(Grant No.2022YFD1400200)the Special Support Plan for High-Level Talent of Shaanxi Provincethe First-Class Universities and Academic Programs of Northwest A&F University.
文摘Pseudomonas syringae pv.actinidiae(Psa)causes destructive kiwifruit bacterial canker by invading vascular tissues across multiple plant organs.However,the cellular mechanism underlying its systemic transmission and cell-to-cell movement within these specialized vascular conduits remains unclear.In this study,a Psa-GFP strain and various microscopic techniques were used to investigate the interaction between kiwifruit and Psa.Our results reveal that Psa strategically exploits host vascular conduits for systemic movement,with the xylem vessel being the predominant avenue.In the phloem,Psa exhibits adaptive alteration in bacterial shape to traverse sieve pores,facilitating its systemic spread along sieve tubes and inducing phloem necrosis.Within the xylem,Psa breaches pit membranes to migrate between adjacent vessels.Furthermore,phloem fibers act as an initial barrier at the early stages of infection,delaying Psa's entry into vascular tissues during its journey to the xylem.Additionally,at the junctions of stem-stem or stem-leaf,branch trace or leaf trace mediates the bacterial organ-to-organ translocation,thus facilitating the systemic progression of disease.In conclusion,our findings shed light on the cellular mechanism employed by Psa to exploit the woody plant's vascular network for infection,thereby enhancing a better understanding of the biology of this poorly defined bacterium.These insights carry implications for the pathogenesis of Psa and other vascular pathogens,offering theoretical guidance for effective control strategies.
基金supported by grants from the National Key R&D Program of China (2021YFA1300701) to J.M.Z.the National Natural Science Foundation of China (31872654) to Z.Y.Z.the Hainan Excellent Talent Team, and the State Key Laboratory of Plant Genomics (SKLPG2016B-2) to J.M.Z
文摘Pseudomonas syringae pv.actinidiae(Psa)causes bacterial canker,a devastating disease threatening the Actinidia fruit industry.In a search for non-host resistance genes against Psa,we find that the nucleotidebinding leucine-rich repeat receptor(NLR)protein ZAR1 from both Arabidopsis and Nicotiana benthamiana(Nb)recognizes Hop Z5 and triggers cell death.The recognition requires ZED1 in Arabidopsis and JIM2 in Nb plants,which are members of the ZRK pseudokinases and known components of the ZAR1 resistosome.Surprisingly,Arabidopsis ZAR1 and RPM1,another NLR known to recognize Hop Z5,confer disease resistance to Hop Z5 in a strain-specific manner.Thus,ZAR1,but not RPM1,is solely required for resistance to P.s.maculicola ES4326(Psm)carrying hop Z5,whereas RPM1 is primarily required for resistance to P.s.tomato DC3000(Pst)carrying hop Z5.Furthermore,the ZAR1-mediated resistance to Psm hop Z5 in Arabidopsis is insensitive to SOBER1,which encodes a deacetylase known to suppress the RPM1-mediated resistance to Pst hop Z5.In addition,hop Z5 enhances P.syringae virulence in the absence of ZAR1 or RPM1 and that SOBER1 abolishes such virulence function.Together the study suggests that ZAR1 may be used for improving Psa resistance in Actinidia and uncovers previously unknown complexity of effectortriggered immunity and effector-triggered virulence.
基金Important National Science & Technology Specific Project (2009Z10603)Hunan Science andTechnology Project (2009FJ3209)
文摘Objective Radix of Actinidiae chinensis,a medicinal plant used in China,is the dry root of Actini-diaceae plant and has been extensively employed to treat cancers of various organs,including the lung,liver and digestive system.However,up to now,its active antitumor and antiviral fractions remain unclear.The main purpose of this study is to identify the antitumor and antiviral sites of Radix of Actinidiae chinensis,which provides evidences for its further development.Methods Radix of Actinidiae chinensis was extracted by the refluxing sequentially with acetidin,ethanol and water,followed by the column chromatography and thin layer chromatography.The antitumor effects on Bel-7402,SW-620 and MDA-MB-231 tumor cells were investigated to screen the active antitumor sites by cell inhibition,the growth curve and the apoptosis staining.Meanwhile,to screen the active anti-hepatovirus fractions,the cell growth and the secretion of HBsAg and HBeAg in HepG2.2.15 cells were evaluated by the MTT test and enzyme-linked immunosorbent assay respectively.Results The acetidin fraction Y(Y1+Y2),the ethanol fraction A(A1+A3+A4) and B(A1+A4+A6),and the fraction compound C(A1+A4+Y1) have strong inhibitive effects on Bel-7402,SW-620 and MDA-MB-231 tumor cell lines.Moreover,the tumor cell apoptosis could be induced by the ethanol fraction B and the fraction compound C.In HepG2.2.15 cells,the treatment indexes of the acetidin fraction Y,the ethanol fraction A and the fraction compound C all exceeded 2 on the secretion of HBsAg,indicating the suppre-ssive effects of them on hepatitis B virus.The fraction yields of A,B and C exceeded 50%(60.28%,54.35% and 62.64% respectively),while that of Y did not(17.7%).Conclusion The ethanol fraction B and the fraction compound C are the antitumor sites of Actinidiae chinensis Radix,while the ethanol fraction A and the fraction compound C are its antiviral sites.
基金supported by grants from the National Key Research and Development Program of China(Grant No.2022YFD1400200)the Special Support Plan for High-Level Talent of Shaanxi Province。
文摘Ambient temperature affects the occurrence and prevalence of plant disease.Most bacterial diseases are damaging at high temperatures.However,kiwifruit bacterial canker caused by Pseudomonas syringae pv.actinidiae(Psa)has been found to be prevalent at relatively cool temperatures,and it is unclear how ambient temperature affects the development of kiwifruit bacterial canker.In this study,basal resistance to Psa was suppressed in kiwifruit at cool growth temperature(16℃)compared with at normal temperature(24℃).In addition,RNA sequence analysis and ethylene content assessment indicated that ethylene modulated kiwifruit resistance to Psa at normal growth temperature and that cool temperature inhibited ethylene accumulation and Psa-induced activation of the ethylene signaling pathway in kiwifruit.Virusmediated silencing of the kiwifruit ethylene signaling gene AcEIN2 suppressed kiwifruit resistance to Psa at normal growth temperature.Exogenous application of ethylene inhibitor 1-methylcyclopropene eliminated the difference in kiwifruit resistance to Psa at 16 and 24℃.Exogenous application of ethylene analogues ethephon induced resistance to Psa in kiwifruit.In conclusion,cool temperatures impair basal resistance to Psa by reducing the activation of ethylene biosynthesis and signaling in kiwifruit.The results provide clues for new strategies to control plant diseases in a context of global environmental change.
基金funded by the National Key Research and Development Program(Grant No.2022YFD1600700)Major Science and Technology Projects of Henan Province(Grant No.221100110400)+3 种基金the China Agriculture Research System of MOF and MARA(Grant No.CARS-26)Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Science(Grant No.CAAS-ASTIP-2023-ZFRI-03)Yunnan Science and Technology Program(Grant No.202205AF150043)Sichuan Science and Technology Program(Grant No.2021YFN0060)。
文摘Waterlogging stress is one of the greatest environmental threats to kiwifruit growth and development.ERF-VII proteins have been demonstrated to play pivotal roles in regulating plant tolerance to waterlogging.Nevertheless,the genome-wide role of ERF-VII in kiwifruit waterlogging stress tolerance remains unclear.Here,we report the function and regulatory network of an ERF-VII transcription factor located to the nucleus,Av ERF73,in kiwifruit waterlogging tolerance.Overexpression of Av ERF73 in Arabidopsis thaliana and A.chinensis cv.Hongyang enhanced waterlogging tolerance in transgenic plants.Furthermore,we performed transcriptome analysis(RNA-seq)and DNA affinity purification sequencing(DAP-seq)to explore the regulatory mechanism of Av ERF73.RNA-seq coupled with DAP-seq showed that Av ERF73 might directly activate Ac NAC022 involved in the“cellular response to hypoxia”process and Ac HMGS1 involved in the mevalonate pathway to respond to waterlogging,which were also confirmed by a dual-luciferase reporter assay.Based on our results,we propose a putative working model for controlling waterlogging tolerance by Av ERF73 in kiwifruit.
基金Supported by the Special Science Foundation of Jiangxi Province(20143ACF60015)National Natural Scientific Fund(31360472)~~
文摘[Objective] The variation of sugar, acid and AsA contents in fruits of ‘Ganmi 6＇ kiwifruit （Actinidia eriantha Benth） were investigated during fruit develop- ment. [Method] Kiwi fruits were randomly taken as materials every 15 days since 20 days after full bloom （DAFB） to 170 DAFB until in mature stage. [Result] The results showed that during fruit development of ‘Ganmi 6＇, the total sugar soluble contents had a rising trend with relatively stable at 95 DAFB, then rose until har- vest with the maximum content （10.35%）. The titratable acid content showed a trend of increasing, then declining, then increase to the harvest content （1.10%）. From the sugar acid ratio, we can knew it decreased in 95 DAFB, then up to the max （9.38）. The changes of AsA contents showed double ‘S＇ shape, decreased af- ter the first increased rapidly, slightly increased and then decreased in the early harvest. [Conclusion] It provided a theoretical basis for scientific cultivation methods to explore the nutrients regulation.
基金The research is supported by grant from the National Natural Science Foundation of China.
文摘Protoplasts isolated from cotyledon-derived calli of Actinidia chinensis var. chinensis (2n = 2x=58) were fused by the PEG method with cotyledon-callus protoplasts of A. deliciosa var. deliciosa (2n = 6x = 174) or with mesophyll protoplasts of A. kolomikta (2n = 2x = 58), respectively. Randomly amplified polymorphic DNA (RAPD) markers and flow cytometry was used to confirm the occurrence of somatic hybrids. RAPD results with some primers surveyed indicated that one clone (A. chinensis + A. deliciosa) and four clones (A. chinensis + A. kolomikta) had RAPD banding patterns which combined the parental banding profiles. Ploidy levels of the (A. chinensis + A. deliciosa) clone were deduced as octoploid (2n = 8x), and the (A. chinensis + A. kolomikta) clones were tetraploid (2n = 4x), triploid (2n = 3x) or pentaploid (2n = 5x). The clones were confirmed as interspecific somatic hybrids in Actinidia.
