摘要
以优质粳稻浙禾香2号为材料,在灌浆初期设置适温31℃/24℃(NT)和高温35℃/28℃(HT)2个温度梯度处理,持续5d、10d和15d后以及成熟收获时分别取样观测分析水稻籽粒淀粉、蛋白质和三磷酸腺苷(ATP)形成关键酶活性及其相关基因表达,以明确灌浆初期高温对水稻籽粒碳氮代谢和能量代谢过程影响的机理。结果表明:(1)与NT相比,HT处理显著降低籽粒重和淀粉相对含量,而蛋白质相对含量呈现上升的趋势。(2)HT处理条件下蔗糖转运基因Os SUT1和Os SUT2相对表达量显著降低,而蔗糖分解酶活性随着处理时间的延长呈先升后降的趋势,导致高温条件下蔗糖供应受到抑制。(3)与NT相比,HT条件下糖酵解关键酶己糖激酶和丙酮酸激酶活性显著下降;而三羧酸循环途径关键酶活性的变化在高温下则表现出明显的差异,柠檬酸合酶、α-酮戊二酸脱氢酶及琥珀酸脱氢酶活性显著下降,异柠檬酸脱氢酶和苹果酸脱氢酶活性显著升高;HT条件下,ATP(三磷酸腺苷)和ADP(二磷酸腺苷)总量与NT无显著差异。(4)与NT相比,HT处理显著降低ADPG焦磷酸化酶活性,同时降低颗粒结合淀粉合成酶和可溶性淀粉合成酶活性,导致直链淀粉合成受阻;淀粉水解相关酶活性呈上升趋势,说明高温促进了籽粒淀粉水解。(5)与NT相比,HT处理条件下籽粒总氮含量有一定上升,但差异未达显著水平,氨基酸含量呈显著上升趋势,其中谷氨酸和α-酮戊二酸含量显著增加;硝酸还原酶和亚硝酸还原酶活性呈下降趋势,而高温对谷氨酸合成酶和谷氨酰胺合成酶活性的影响与适温无显著差异。所以,本试验条件下,高温下籽粒发育受阻的主要原因是蔗糖转运受阻而不是蔗糖利用受抑,同时高温导致糖酵解和三羧酸循环紊乱;高温下籽粒淀粉合成受阻,同时淀粉水解增强;高温下三羧酸循环过程紊乱,α-酮戊二酸积累增加是蛋白质含量上升的原因之一�
Global temperature increase caused by climate warming is an obvious feature of climate change in recent years.With the global temperature rising,high temperature and heat damage of rice occur frequently.Especially in southern China,high temperature during grain filling has become an important factor restricting rice quality.The optimumaverage temperature for the grain-filling stage of rice is about 21℃.High temperature above 35℃will significantly reduce the yield and quality of rice.The physiological process of carbon and nitrogen metabolism plays a key role in grain filling.As an important component of grain dry weight,the metabolism of starch and protein is affected by the physiological processes of carbon and nitrogen metabolismIn order to clarify the effect of high temperature on the physiological characteristics of carbon and nitrogen metabolism of rice grains during the early stage of filling,In this experiment,"Zhehexiang2",a Japonica rice with good quality,was used as material.Two temperature gradients(31℃/24℃(NT))and 35℃/28℃(HT)were set up at the early stage of grain filling.After 5 days,10 days and 15 days,and at harvest,the activities of key enzymes and related gene expression of starch,protein and adenosine triphosphate(ATP)formation in rice grain were observed and analyzed to determine the high temperature at the early stage of grain filling mechanism of effects on carbon,nitrogen and energy metabolism in rice grain.The results showed that,(1)compared with NT,HT treatment significantly reduced grain weight and starch content,while protein content increased.(2)Under HT treatment,the relative expression of sucrose transport genes Os SUT1 and Os SUT2 decreased significantly,while the activity of sucrose catabolic enzymes increased first and then decreased with the extension of the treatment time,resulting in the inhibition of sucrose supply under high temperature.(3)Compared with NT,the activities of key glycolytic enzymes hexokinase and pyruvate kinase decreased significantlyunder HT condit
作者
王军可
王亚梁
陈惠哲
向镜
张义凯
朱德峰
张玉屏
WANG Jun-ke;WANG Ya-liang;CHEN Hui-zhe;XIANG Jing;ZHANG Yi-kai;ZHU De-feng;ZHANG Yu-ping(China National Rice Research Institute/State Key Laboratory of Rice Biology,Hangzhou 311400,China)
出处
《中国农业气象》
CSCD
北大核心
2020年第12期774-784,共11页
Chinese Journal of Agrometeorology
基金
浙江省基金(LQ20C130009)
国家重点研发计划项目(2017YFD0300409)
现代农业产业技术体系建设专项(CARS-01-22)。
关键词
水稻
灌浆期高温
碳氮代谢
能量代谢
蔗糖转运
蔗糖利用
淀粉合成
淀粉水解
Rice
High temperature during filling
Carbon and nitrogen metabolism
Energy metabolism
Sucrose transport
Sucrose utilization
Starch synthesis
Starch hydrolysis
