丁二醇对热胁迫下匍匐翦股颖内源激素及其相关基因表达水平的调控

Regulatory effects of butanediol on the expression level of endogenous hormones and related genes in creeping bentgrass under heat stress

为了提高匍匐翦股颖的越夏能力,本试验以匍匐翦股颖Penn A4为材料,模拟设置人工气候热胁迫(37℃/32℃,昼/夜),通过叶面喷施300μmol·L2,3-丁二醇(BD),测定分析BD对Penn A4盆栽苗在热胁迫第0(BD预处理前)、7、42天及恢复常温第10天时叶片内源激素含量及其相关基因表达的影响。结果表明:外源BD提高了热胁迫7 d时Penn A4细胞分裂素、赤霉素3、茉莉酸类含量,降低了生长素、水杨酸、脱落酸、1-氨基环丙烷羧酸含量,并抑制了其相关基因的表达,从而促进了蒸腾降温及植株营养生长;胁迫42 d时,BD上调各个激素相关基因的表达量,通过促进内源激素运输降低了叶片活性激素含量,从而抑制了植株营养生长,为Penn A4抵御长时间热胁迫保存了能量,并提高了其存活几率。综上,BD可通过调节内源激素代谢加快短期胁迫下Penn A4生长速率及蒸腾散热,抑制长期胁迫下植株的衰老和生长速率来提高Penn A4耐热性。

This research investigated ways to improve the heat resistance of creeping bentgrass(Agrostis stolonifera)in the context of use as a turfgrass in a global warming environment.Potted seedlings of the variety Penn A4 were studied under a simulated high temperature environment(37℃/32℃,day/night)and subjected to treatments involving foliar spraying of 300μmol·L2,3-butanediol(BD)to examine effects on leaf endogenous hormone content and the related gene expression.Seedlings received a BD pretreatment before being exposed to heat stress for0,7 or 42 days before BD pretreatment,and then were allowed to recover at optimal temperature for 10 days.For seedlings subject to 7 days of heat stress it was found that BD application increased the levels of cytokinin,gibberellins(GA3)and jasmonic acid,decreased levels of auxin,salicylic acid,abscisic acid,and 1-aminocyclopropane carboxylic acid,and decreased the expression of related genes,thereby accelerating transpirationdriven cooling and plant vegetative growth.In addition,in plants subject to 42 days of stress,BD pre-treatment upregulated the expression levels of various hormone-related genes,and reduced leaf hormone content by promoting endogenous hormone transport,thus inhibiting plant vegetative growth,and an energy saving whereby Penn A4 seedlings were able to resist long-term heat stress,and improving their survival probability.In summary,by regulating endogenous hormone metabolism to accelerate the growth rate and transpiration-induced cooling of Penn A4 under short-term stress,and by inhibiting the senescence and growth rate of plants under long-term stress,BD improved heat tolerance of Penn A4creeping bentgrass.