Plants adaptively change their cell wall composition and structure during their growth,development,and interactions with environmental stresses.Dirigent proteins(DIRs)contribute to environmental adaptations by dynamic...Plants adaptively change their cell wall composition and structure during their growth,development,and interactions with environmental stresses.Dirigent proteins(DIRs)contribute to environmental adaptations by dynamically reorganizing the cell wall and/or by generating defense compounds.A maize DIR,ZmDRR206,was previously reported to play a dominant role in regulation of storage nutrient accumulation in endosperm during maize kernel development.Here we show that ZmDRR206 mediates maize seedling growth and disease resistance by coordinately regulating biosynthesis of cell wall components for cell-wall integrity(CWI)maintenance.Expression of ZmDRR206 was induced in maize seedlings upon pathogen infection.ZmDRR206 overexpression in maize resulted in reduced seedling growth and photosynthetic activity but increased disease resistance and drought tolerance,revealing a tradeoff between growth and defense.Consistently,ZmDRR206 overexpression reduced the contents of primary metabolites and down-regulated genes involved in photosynthesis,while increasing the contents of major cell wall components,defense phytohormones,and defense metabolites,and up-regulated genes involved in defense and cell-wall biosynthesis in seedlings.ZmDRR206-overexpressing seedlings were resistant to cell-wall stress imposed by isoxaben,and ZmDRR206 physically interacted with ZmCesA10,which is a cellulose synthase unit.Our findings suggest a mechanism by which ZmDRR206 coordinately regulates biosynthesis of cell-wall components for CWI maintenance during maize seedling growth,and might be exploited for breeding strong disease resistance in maize.展开更多
Grain water content(GWC)is a key determinant for mechanical harvesting of maize(Zea mays).In our previous research,we identified a quantitative trait locus,qGWC1,associated with GWC in maize.Here,we examined near-isog...Grain water content(GWC)is a key determinant for mechanical harvesting of maize(Zea mays).In our previous research,we identified a quantitative trait locus,qGWC1,associated with GWC in maize.Here,we examined near-isogenic lines(NILs)NILL and NILH that differed at the qGWC1 locus.Lower GWC in NILL was primarily attributed to reduced grain water weight(GWW)and smaller fresh grain size,rather than the accumulation of dry matter.The difference in GWC between the NILs became more pronounced approximately 35 d after pollination(DAP),arising from a faster dehydration rate in NILL.Through an integrated analysis of the transcriptome,proteome,and metabolome,coupled with an examination of hormones and their derivatives,we detected a marked decrease in JA,along with an increase in cytokinin,storage forms of IAA(IAA-Glu,IAA-ASP),and IAA precursor IPA in immature NILL kernels.During kernel development,genes associated with sucrose synthases,starch biosynthesis,and zein production in NILL,exhibited an initial up-regulation followed by a gradual down-regulation,compared to those in NILH.This discovery highlights the crucial role of phytohormone homeostasis and genes related to kernel development in balancing GWC and dry matter accumulation in maize kernels.展开更多
基金the Ministry of Agriculture and Rural Affairs of the People’s Republic of China(2018ZX0800917B)grant from Yunnan Provincial Science and Technology Department(202005AF150026).
文摘Plants adaptively change their cell wall composition and structure during their growth,development,and interactions with environmental stresses.Dirigent proteins(DIRs)contribute to environmental adaptations by dynamically reorganizing the cell wall and/or by generating defense compounds.A maize DIR,ZmDRR206,was previously reported to play a dominant role in regulation of storage nutrient accumulation in endosperm during maize kernel development.Here we show that ZmDRR206 mediates maize seedling growth and disease resistance by coordinately regulating biosynthesis of cell wall components for cell-wall integrity(CWI)maintenance.Expression of ZmDRR206 was induced in maize seedlings upon pathogen infection.ZmDRR206 overexpression in maize resulted in reduced seedling growth and photosynthetic activity but increased disease resistance and drought tolerance,revealing a tradeoff between growth and defense.Consistently,ZmDRR206 overexpression reduced the contents of primary metabolites and down-regulated genes involved in photosynthesis,while increasing the contents of major cell wall components,defense phytohormones,and defense metabolites,and up-regulated genes involved in defense and cell-wall biosynthesis in seedlings.ZmDRR206-overexpressing seedlings were resistant to cell-wall stress imposed by isoxaben,and ZmDRR206 physically interacted with ZmCesA10,which is a cellulose synthase unit.Our findings suggest a mechanism by which ZmDRR206 coordinately regulates biosynthesis of cell-wall components for CWI maintenance during maize seedling growth,and might be exploited for breeding strong disease resistance in maize.
基金supported by the Jiangsu province Seed Industry Revitalization project[JBGS(2021)002]Beijing Germplasm Creation and Variety Selection and Breeding Joint Project[NY2023-180].
文摘Grain water content(GWC)is a key determinant for mechanical harvesting of maize(Zea mays).In our previous research,we identified a quantitative trait locus,qGWC1,associated with GWC in maize.Here,we examined near-isogenic lines(NILs)NILL and NILH that differed at the qGWC1 locus.Lower GWC in NILL was primarily attributed to reduced grain water weight(GWW)and smaller fresh grain size,rather than the accumulation of dry matter.The difference in GWC between the NILs became more pronounced approximately 35 d after pollination(DAP),arising from a faster dehydration rate in NILL.Through an integrated analysis of the transcriptome,proteome,and metabolome,coupled with an examination of hormones and their derivatives,we detected a marked decrease in JA,along with an increase in cytokinin,storage forms of IAA(IAA-Glu,IAA-ASP),and IAA precursor IPA in immature NILL kernels.During kernel development,genes associated with sucrose synthases,starch biosynthesis,and zein production in NILL,exhibited an initial up-regulation followed by a gradual down-regulation,compared to those in NILH.This discovery highlights the crucial role of phytohormone homeostasis and genes related to kernel development in balancing GWC and dry matter accumulation in maize kernels.
