Temperature sensitivity and tolerance play a key role in plant survival and production.Perennial ryegrass(Lolium perenne L.),widely cultivated in cool-season for forage supply and turfgrass,is extremely susceptible to...Temperature sensitivity and tolerance play a key role in plant survival and production.Perennial ryegrass(Lolium perenne L.),widely cultivated in cool-season for forage supply and turfgrass,is extremely susceptible to high temperatures,therefore serving as an excellent grass for dissecting the genomic and genetic basis of high-temperature adaptation.In this study,expression analysis revealed that LpHsfA2,an important gene associated with high-temperature tolerance in perennial ryegrass,is rapidly and substantially induced under heat stress.Additionally,heat-tolerant varieties consistently display elevated expression levels of LpHsfA2 compared with heat-sensitive ones.Comparative haplotype analysis of the LpHsfA2 promoter indicated an uneven distribution of two haplotypes(HsfA2^(Hap1) and HsfA2^(Hap2)) across varieties with differing heat tolerance.Specifically,the HsfA2^(Hap1) allele is predominantly present in heat-tolerant varieties,while the HsfA2^(Hap2) allele exhibits the opposite pattern.Overexpression of LpHsfA2 confers enhanced thermotolerance,whereas silencing of LpHsfA2 compromises heat tolerance.Furthermore,LpHsfA2 orchestrates its protective effects by directly binding to the promoters of LpHSP18.2 and LpAPX1 to activate their expression,preventing the non-specific misfolding of intracellular protein and the accumulation of reactive oxygen species in cells.Additionally,LpHsf A4 and LpHsf A5 were shown to engage directly with the promoter of LpHsfA2,upregulating its expression as well as the expression of LpHSP18.2 and LpAPX1,thus contributing to enhanced heat tolerance.Markedly,LpHsfA2 possesses autoregulatory ability by directly binding to its own promoter to modulate the self-transcription.Based on these findings,we propose a model for modulating the thermotolerance of perennial ryegrass by precisely regulating the expression of LpHsfA2.Collectively,these findings provide a scientific basis for the development of thermotolerant perennial ryegrass cultivars.展开更多
基金supported by the National Key R&D Program of China(2022YFF1003200)the National Natural Science Foundation of China(NSFC)(Grant Nos.32001394,32102431 and 32101430)+2 种基金the Science&Technology Specific Projects in Agricultural High-tech Industrial Demonstration Area of the Yellow River Delta(Grant No.2022SZX13)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA26050201)the Major Science and Technology Innovation Project of Shandong Province(2022LZGC018)。
文摘Temperature sensitivity and tolerance play a key role in plant survival and production.Perennial ryegrass(Lolium perenne L.),widely cultivated in cool-season for forage supply and turfgrass,is extremely susceptible to high temperatures,therefore serving as an excellent grass for dissecting the genomic and genetic basis of high-temperature adaptation.In this study,expression analysis revealed that LpHsfA2,an important gene associated with high-temperature tolerance in perennial ryegrass,is rapidly and substantially induced under heat stress.Additionally,heat-tolerant varieties consistently display elevated expression levels of LpHsfA2 compared with heat-sensitive ones.Comparative haplotype analysis of the LpHsfA2 promoter indicated an uneven distribution of two haplotypes(HsfA2^(Hap1) and HsfA2^(Hap2)) across varieties with differing heat tolerance.Specifically,the HsfA2^(Hap1) allele is predominantly present in heat-tolerant varieties,while the HsfA2^(Hap2) allele exhibits the opposite pattern.Overexpression of LpHsfA2 confers enhanced thermotolerance,whereas silencing of LpHsfA2 compromises heat tolerance.Furthermore,LpHsfA2 orchestrates its protective effects by directly binding to the promoters of LpHSP18.2 and LpAPX1 to activate their expression,preventing the non-specific misfolding of intracellular protein and the accumulation of reactive oxygen species in cells.Additionally,LpHsf A4 and LpHsf A5 were shown to engage directly with the promoter of LpHsfA2,upregulating its expression as well as the expression of LpHSP18.2 and LpAPX1,thus contributing to enhanced heat tolerance.Markedly,LpHsfA2 possesses autoregulatory ability by directly binding to its own promoter to modulate the self-transcription.Based on these findings,we propose a model for modulating the thermotolerance of perennial ryegrass by precisely regulating the expression of LpHsfA2.Collectively,these findings provide a scientific basis for the development of thermotolerant perennial ryegrass cultivars.
