土壤水分亏缺和大气CO_(2)浓度升高对冬小麦光合特性的影响  

Effects of soil water deficit and elevated atmospheric CO_(2) concentration on leaf photosynthesis of winter wheat

作　　者：郑云普[1] 常志杰 韩怡[1] 卢云泽 陈文娜 田银帅 殷嘉伟 郝立华[1,3] ZHENG Yun-Pu;CHANG Zhi-Jie;HAN Yi;LU Yun-Ze;CHEN Wen-Na;TIAN Yin-Shuai;YIN Jia-Wei;HAO Li-Hua(School of Water Conservancy and Hydropower,Hebei University of Engineering,Handan 056038,Hebei,China;School of Landscape and Eco-logical Engineering,Hebei University of Engineering,Handan 056038,Hebei,China;College of Horticulture,Nanjing Agricultural University,Nanjing 210095,Jiangsu,China)

机构地区：[1]河北工程大学水利水电学院,河北邯郸056038 [2]河北工程大学园林与生态工程学院,河北邯郸056038 [3]南京农业大学园艺学院,江苏南京210095

出　　处：《作物学报》2022年第11期2920-2933,共14页Acta Agronomica Sinica

基　　金：国家自然科学基金项目(32071608);河北省自然科学基金项目(C2020402026,E2021402031)资助。

摘　　要：为深入理解未来大气CO_(2)浓度([CO_(2)])升高背景下农田生态系统结构与功能对土壤水分亏缺的响应机制,利用可精准控制[CO_(2)]的大型环境生长箱,研究了土壤水分亏缺和大气[CO_(2)]升高对冬小麦气孔特征、净光合速率、水分利用效率、叶片碳氮含量、非结构性碳水化合物含量、核酮糖-1,5-二磷酸羧化酶/加氧酶(Rubisco)活性及其基因表达量的影响。本研究结果表明,水分亏缺导致冬小麦的总生物量和净光合速率(P_(n))分别相比对照降低33%和29%,而[CO_(2)]升高可以在一定程度上缓解水分亏缺对冬小麦生长及生理过程造成的不利影响。同时,水分亏缺还使冬小麦气孔开度及其空间分布格局规则性的降低,但高[CO_(2)]可以通过增加气孔密度和提高气孔分布的规则程度,进一步优化冬小麦叶片的气体交换效率。另外,[CO_(2)]升高增加水分亏缺条件下冬小麦的P_(n),但同时却导致蒸腾速率(T_(r))降低25%,从而提高叶片的瞬时水分利用效率(WUEI)61%。此外,水分亏缺条件下[CO_(2)]升高不仅导致Rubisco酶初始活性、活化率以及可溶性蛋白含量分别增加66%、38%和15%,而且还分别提高Rubisco酶编码基因RbcL3和RbcS2的表达水平453%和417%。上述结果表明,水分亏缺条件下,[CO_(2)]升高可以通过调整气孔特征和Rubisco酶活性及其编码基因表达水平,进一步优化冬小麦的气体交换效率,从而提高植株生物量、净光合速率以及水分利用效率。研究结果将为深入理解未来气候变化背景下冬小麦响应[CO_(2)]升高和水分亏缺的生理及分子机制提供理论依据。To understand the mechanisms of agricultural ecosystem structure and function in response to soil water deficit under future elevated atmospheric CO_(2) concentration,we examined the effects of soil water deficit and elevated CO_(2) concentration([CO_(2)])on the stomatal traits,leaf photosynthesis,water use efficiency as well as Rubisco activity and gene expression of winter wheat with environmental growth chambers,whereby the[CO_(2)]was controlled accurately with CO_(2) sensors.Our results showed that water deficit significantly decreased the plant biomass and net photosynthesis rates(P_(n))of winter wheat by 33%and 29%,whereas elevated[CO_(2)]partially mitigated the negative effects of water deficit on plant growth and physiological processes of winter wheat.Meanwhile,water deficit also reduced the stomatal width and regularity of stomatal distribution pattern on winter wheat leaves,but higher[CO_(2)]could optimize the leaf gas exchange efficiency with more regular distribution pattern of stomata.Moreover,elevated[CO_(2)]not only enhanced the P_(n) of winter wheat plants under water deficit,but also substantially reduced the transpiration rates(T_(r))by 25%,and thus elevated[CO_(2)]increased the water use efficiency by 61%when winter wheat plants subjected to water deficit.In addition,elevated[CO_(2)]boosted the initial activity and activation state of Rubisco as well as soluble protein content by 66%,38%,and 15%,and meanwhile significantly enhanced the gene expression levels of RbcL3 and RbcS2 by 453%and 417%,respectively.These results suggested that elevated[CO_(2)]may optimize leaf gas exchange through modifying stomatal traits as well as the activity and gene express of Rubisco,and thus increased plant biomass,P_(n),and water use efficiency to efficiently alleviate the physiological stress of water deficit on growth and development processes of winter wheat.Our findings may not only provide data for further understanding the impacts of water deficit on grain yield and water use efficiency of winter wheat un

关 键 词：土壤水分亏缺 CO_(2)浓度升高 冬小麦 气孔特征 光合性能 Rubisco基因表达 

分 类 号：S512.11[农业科学—作物学]