Drought stress caused by insufficient irrigation or precipitation impairs agricultural production worldwide.In this study,a two-year field experiment was conducted to investigate the effect of coronatine(COR),a functi...Drought stress caused by insufficient irrigation or precipitation impairs agricultural production worldwide.In this study,a two-year field experiment was conducted to investigate the effect of coronatine(COR),a functional analog of jasmonic acid(JA),on maize drought resistance.The experiment included two water treatments(rainfed and irrigation),four COR concentrations(mock,0μmol L^(-1);A1,0.1μmol L^(-1);A2,1μmol L^(-1);A3,10μmol L^(-1))and two maize genotypes(Fumin 985(FM985),a drought-resistant cultivar and Xianyu 335(XY335),a drought-sensitive cultivar).Spraying 1μmol L^(-1)COR at seedling stage increased surface root density and size,including root dry matter by 12.6%,projected root area by 19.0%,average root density by 51.9%,and thus root bleeding sap by 28.2%under drought conditions.COR application also increased leaf area and SPAD values,a result attributed to improvement of the root system and increases in abscisic acid(ABA),JA,and salicylic acid(SA)contents.The improvement of leaves and roots laid the foundation for increasing plant height and dry matter accumulation.COR application reduced anthesis and silking interval,increasing kernel number per ear.COR treatment at 1μmol L^(-1)increased the yield of XY335 and FM985 by 7.9%and 11.0%,respectively.Correlation and path analysis showed that grain yields were correlated with root dry weight and projected root area,increasing maize drought resistance mainly via leaf area index and dry matter accumulation.Overall,COR increased maize drought resistance mainly by increasing root dry weight and root area,with 1μmol L-^(-1)COR as an optimal concentration.展开更多
Mulberry bacterial blight is caused by Pseudomonas syringae pv. mori. Coronatine （COR）, a phytotoxin and phytohormone produced by several strains of Pseudomonas syringae, is suggested to have an important role in pa...Mulberry bacterial blight is caused by Pseudomonas syringae pv. mori. Coronatine （COR）, a phytotoxin and phytohormone produced by several strains of Pseudomonas syringae, is suggested to have an important role in pathogen-plant interaction. The aim of our study was to examine the influence of COR on mul- berry in the process of pathogen infection. Results showed that COR could suppress stomatal closure induced by pathogen-associated molecular patterns （PAMPS）, assist pathogenic bacteria into the leaves, and promote bacterial proliferation in the tissues. High-concentration （1 μmol/L） exogenous COR and COR-producing bacterial pathogen induced chlorosis symptom and decrease of chlorophyll content, contrary to the effects of low-concentration （0.001 μmol/L） exogenous COR and non-COR-preducing bacterial pathogen. Treatments with COR and DC3000 enhanced the production of reactive oxygen species （ ROS）, namely, hydrogen peroxide （H2O2 ） and superexide anion （O2-）, but there were two H2O2 peaks at 1 -3 hpi and 8 -24 hpi in the DC3000-treated leaves while only one peak at 1 -3 h was observed 1 -3 h in the COR-treated ones. H202 could kill the pathogenic bacteria, on the other hand, it also acted as an upstream signaling molecule to promote nitric oxide （NO） production to further participate in the signaling pathway. Enzymatic antioxidant systems （superoxide dismutase, peroxidase and catalase） and defensive enzyme systems （lipoxygenase, polyphenol oxidase and phenylalnine ammonialyase） were activated by COR. Therefore, COR could cooperate on the inva- sion and proliferation of COR-producing bacterial pathogens, and induce the chloresis symptom in mulberry. At the same time, exogenously applied COR also could enhance the resistance to P. syringae pv. mori by production of signal molecules to activate signaling pathway and promoting defense-related metabolism.展开更多
[Objective] The objective of this research was to examine the effects of COR on anthocyanin and starch content in storage roots of two PFS genotypes, and to explore the relationships between anthocyanin synthesis and ...[Objective] The objective of this research was to examine the effects of COR on anthocyanin and starch content in storage roots of two PFS genotypes, and to explore the relationships between anthocyanin synthesis and starch accumula- tion. [Method] A field experiment was carried out to determine the changes in yielc components, yield, contents of anthocyanin and starch, activities of phenylalanine ammonia-lyase （PAL） and adenosine 5-diphosphate glucose pyrophosphorylase （AG- Pase） in two genotypes of PFS （Ipomoea batatas L., var. ＇Ayamurasaki＇ and ＇Jishu18＇）. [Result] The application of COR significantly increased starch and antho- cyanin content in storage roots of Jishu18 across developmental stages by inducing the activities of PAL and AGPase, and finally enhanced yield by promoting fresh weight of storage roots. Ayamurasaki was insensitive to treatment with COR al- though its PAL activity temporally increased. The starch and anthocyanin content of Aya, and the anthocyanin content of Jishu18 increased progressively across devel- opmental stages with or without COR application, but the starch content of Jishu18 increased initially, then decreased before increasing again without application of COR. Treatment with COR reduced downward trend of starch accumulation in Jishu18. Thus, the effect of COR on accumulation of anthocyanin and starch in storage roots of PFS differs according to genotypes. [Conclusion] The application of 0.05 μmol/L COR may increase starch and anthocyanin content in PFS genotypes with lower starch and anthocyanin content in storage roots.展开更多
Water uptake is crucial for crop growth and development and drought stress tolerance. The water channel aquaporins(AQP) play important roles in plant water uptake. Here, we discovered that a jasmonic acid analog, coro...Water uptake is crucial for crop growth and development and drought stress tolerance. The water channel aquaporins(AQP) play important roles in plant water uptake. Here, we discovered that a jasmonic acid analog, coronatine(COR), enhanced maize(Zea mays) root water uptake capacity under artificial water deficiency conditions. COR treatment induced the expression of the AQP gene Plasma membrane intrinsic protein 2;5(ZmPIP2;5).In vivo and in vitro experiments indicated that COR also directly acts on ZmPIP2;5 to improve water uptake in maize and Xenopus oocytes. The leaf water potential and hydraulic conductivity of roots growing under hyperosmotic conditions were higher in ZmPIP2;5-overexpression lines and lower in the zmpip2;5 knockout mutant, compared to wild-type plants. Based on a comparison between ZmPIP2;5 and other PIP2s, we predicted that COR may bind to the functional site in loop E of ZmPIP2;5. We confirmed this prediction by surface plasmon resonance technology and a microscale thermophoresis assay, and showed that deleting the binding motif greatly reduced COR binding. We identified the N241 residue as the COR-specific binding site, which may activate the channel of the AQP tetramer and increase water transport activity,which may facilitate water uptake under hyperosmotic stress.展开更多
With the aim to determine whether coronatine （COR） alleviates drought stress on wheat, two winter wheat （Triticum aestivum L.） cultivars, ChangWu134 （drought-tolerant） and Shan253 （drought-sensitive） were stud...With the aim to determine whether coronatine （COR） alleviates drought stress on wheat, two winter wheat （Triticum aestivum L.） cultivars, ChangWu134 （drought-tolerant） and Shan253 （drought-sensitive） were studied under hydroponic conditions. Seedlings at the three-leaf stage were eultured in a Hoagland solution containing COR at 0.1 ~M for 24 h, and then exposed to 20% polyethylene glycol 6000 （PEG- 6000）. Under simulated drought （SD）, COR increased the dry weight of shoots and roots of the two cultivars significantly; the root/shoot ratio also increased by 30% for Shan253 and 40% for ChangWu134. Both cultivars treated with COR under SD （0.1COR-I-PEG） maintained significantly higher relative water content, photosynthesis, transpiration, intercellular concentration of CO2 and stomatal conductance in leaves than those not treated with PEG. Under drought, COR significantly decreased the relative conductivity and malondialdehyde production, and the loss of 1,1-diphenyl-2-picrylhydrazyl scavenging activity in leaves was significantly alleviated in COR-treated plants. The activity of peroxidase, catalase, glutathione reductase and ascorbate peroxidase were adversely affected by drought. Leaves of plants treated with COR under drought produced less abscisic acid （ABA） than those not treated. Thus, COR might alleviate drought effects on wheat by reducing active oxygen species production, activating antioxidant enzymes and changing the ABA level.展开更多
基金funded by National Key Research and Development Program of China(2017YFD0300405-2)。
文摘Drought stress caused by insufficient irrigation or precipitation impairs agricultural production worldwide.In this study,a two-year field experiment was conducted to investigate the effect of coronatine(COR),a functional analog of jasmonic acid(JA),on maize drought resistance.The experiment included two water treatments(rainfed and irrigation),four COR concentrations(mock,0μmol L^(-1);A1,0.1μmol L^(-1);A2,1μmol L^(-1);A3,10μmol L^(-1))and two maize genotypes(Fumin 985(FM985),a drought-resistant cultivar and Xianyu 335(XY335),a drought-sensitive cultivar).Spraying 1μmol L^(-1)COR at seedling stage increased surface root density and size,including root dry matter by 12.6%,projected root area by 19.0%,average root density by 51.9%,and thus root bleeding sap by 28.2%under drought conditions.COR application also increased leaf area and SPAD values,a result attributed to improvement of the root system and increases in abscisic acid(ABA),JA,and salicylic acid(SA)contents.The improvement of leaves and roots laid the foundation for increasing plant height and dry matter accumulation.COR application reduced anthesis and silking interval,increasing kernel number per ear.COR treatment at 1μmol L^(-1)increased the yield of XY335 and FM985 by 7.9%and 11.0%,respectively.Correlation and path analysis showed that grain yields were correlated with root dry weight and projected root area,increasing maize drought resistance mainly via leaf area index and dry matter accumulation.Overall,COR increased maize drought resistance mainly by increasing root dry weight and root area,with 1μmol L-^(-1)COR as an optimal concentration.
基金Supported by the Science and Technology Support Program of the Jiangsu Province(BE2012365)the Modern Agro-industry Technology Research System of China(CARS-22)
文摘Mulberry bacterial blight is caused by Pseudomonas syringae pv. mori. Coronatine （COR）, a phytotoxin and phytohormone produced by several strains of Pseudomonas syringae, is suggested to have an important role in pathogen-plant interaction. The aim of our study was to examine the influence of COR on mul- berry in the process of pathogen infection. Results showed that COR could suppress stomatal closure induced by pathogen-associated molecular patterns （PAMPS）, assist pathogenic bacteria into the leaves, and promote bacterial proliferation in the tissues. High-concentration （1 μmol/L） exogenous COR and COR-producing bacterial pathogen induced chlorosis symptom and decrease of chlorophyll content, contrary to the effects of low-concentration （0.001 μmol/L） exogenous COR and non-COR-preducing bacterial pathogen. Treatments with COR and DC3000 enhanced the production of reactive oxygen species （ ROS）, namely, hydrogen peroxide （H2O2 ） and superexide anion （O2-）, but there were two H2O2 peaks at 1 -3 hpi and 8 -24 hpi in the DC3000-treated leaves while only one peak at 1 -3 h was observed 1 -3 h in the COR-treated ones. H202 could kill the pathogenic bacteria, on the other hand, it also acted as an upstream signaling molecule to promote nitric oxide （NO） production to further participate in the signaling pathway. Enzymatic antioxidant systems （superoxide dismutase, peroxidase and catalase） and defensive enzyme systems （lipoxygenase, polyphenol oxidase and phenylalnine ammonialyase） were activated by COR. Therefore, COR could cooperate on the inva- sion and proliferation of COR-producing bacterial pathogens, and induce the chloresis symptom in mulberry. At the same time, exogenously applied COR also could enhance the resistance to P. syringae pv. mori by production of signal molecules to activate signaling pathway and promoting defense-related metabolism.
基金Supported by National Sweetpotato Industry Technology System(nycytx-16-B-10)
文摘[Objective] The objective of this research was to examine the effects of COR on anthocyanin and starch content in storage roots of two PFS genotypes, and to explore the relationships between anthocyanin synthesis and starch accumula- tion. [Method] A field experiment was carried out to determine the changes in yielc components, yield, contents of anthocyanin and starch, activities of phenylalanine ammonia-lyase （PAL） and adenosine 5-diphosphate glucose pyrophosphorylase （AG- Pase） in two genotypes of PFS （Ipomoea batatas L., var. ＇Ayamurasaki＇ and ＇Jishu18＇）. [Result] The application of COR significantly increased starch and antho- cyanin content in storage roots of Jishu18 across developmental stages by inducing the activities of PAL and AGPase, and finally enhanced yield by promoting fresh weight of storage roots. Ayamurasaki was insensitive to treatment with COR al- though its PAL activity temporally increased. The starch and anthocyanin content of Aya, and the anthocyanin content of Jishu18 increased progressively across devel- opmental stages with or without COR application, but the starch content of Jishu18 increased initially, then decreased before increasing again without application of COR. Treatment with COR reduced downward trend of starch accumulation in Jishu18. Thus, the effect of COR on accumulation of anthocyanin and starch in storage roots of PFS differs according to genotypes. [Conclusion] The application of 0.05 μmol/L COR may increase starch and anthocyanin content in PFS genotypes with lower starch and anthocyanin content in storage roots.
基金supported by the National Key Research and Development Program of China (2016YFD0300102-4)。
文摘Water uptake is crucial for crop growth and development and drought stress tolerance. The water channel aquaporins(AQP) play important roles in plant water uptake. Here, we discovered that a jasmonic acid analog, coronatine(COR), enhanced maize(Zea mays) root water uptake capacity under artificial water deficiency conditions. COR treatment induced the expression of the AQP gene Plasma membrane intrinsic protein 2;5(ZmPIP2;5).In vivo and in vitro experiments indicated that COR also directly acts on ZmPIP2;5 to improve water uptake in maize and Xenopus oocytes. The leaf water potential and hydraulic conductivity of roots growing under hyperosmotic conditions were higher in ZmPIP2;5-overexpression lines and lower in the zmpip2;5 knockout mutant, compared to wild-type plants. Based on a comparison between ZmPIP2;5 and other PIP2s, we predicted that COR may bind to the functional site in loop E of ZmPIP2;5. We confirmed this prediction by surface plasmon resonance technology and a microscale thermophoresis assay, and showed that deleting the binding motif greatly reduced COR binding. We identified the N241 residue as the COR-specific binding site, which may activate the channel of the AQP tetramer and increase water transport activity,which may facilitate water uptake under hyperosmotic stress.
基金supported by grants from the National High Technology Research and Development Program of China(2006AA10A213)the Teaching and Research Award Program for Outstanding Young Teachers in Higher Educational Institutions of the Ministry of Education,China
文摘With the aim to determine whether coronatine （COR） alleviates drought stress on wheat, two winter wheat （Triticum aestivum L.） cultivars, ChangWu134 （drought-tolerant） and Shan253 （drought-sensitive） were studied under hydroponic conditions. Seedlings at the three-leaf stage were eultured in a Hoagland solution containing COR at 0.1 ~M for 24 h, and then exposed to 20% polyethylene glycol 6000 （PEG- 6000）. Under simulated drought （SD）, COR increased the dry weight of shoots and roots of the two cultivars significantly; the root/shoot ratio also increased by 30% for Shan253 and 40% for ChangWu134. Both cultivars treated with COR under SD （0.1COR-I-PEG） maintained significantly higher relative water content, photosynthesis, transpiration, intercellular concentration of CO2 and stomatal conductance in leaves than those not treated with PEG. Under drought, COR significantly decreased the relative conductivity and malondialdehyde production, and the loss of 1,1-diphenyl-2-picrylhydrazyl scavenging activity in leaves was significantly alleviated in COR-treated plants. The activity of peroxidase, catalase, glutathione reductase and ascorbate peroxidase were adversely affected by drought. Leaves of plants treated with COR under drought produced less abscisic acid （ABA） than those not treated. Thus, COR might alleviate drought effects on wheat by reducing active oxygen species production, activating antioxidant enzymes and changing the ABA level.
