气候变暖与干旱复合胁迫对小麦幼苗亚细胞铜、锰动态积累和分布的影响

Effects of combined climate warming and drought stresses on the dynamic accumulation and distribution of subcellular Cu and Mn components in wheat seedlings

全球变暖引发的增温、干旱等多重逆境胁迫已威胁到全球粮食安全及人类健康.以小麦(Triticum aestivum)幼苗为研究对象,通过人工气候室模拟实验,探讨增温与干旱复合逆境胁迫下Cu、Mn元素在小麦幼苗亚细胞水平的动态积累及分布影响,旨在探索多重逆境胁迫下,作物在亚细胞层面的矿质养分响应动态及机理.结果显示,随胁迫水平增加,小麦幼苗根、叶部Cu富集均显著下降,根部Mn富集下降,叶部则增加.根、叶部Cu富集系数最低分别下降至对照的0.50和0.31倍;根部Mn富集系数最低下降至对照的0.70倍,叶部Mn最高增加至对照的1.40倍.根、叶部各亚细胞组分Cu含量随胁迫程度增加而降低,根部各亚细胞组分Mn含量均降低,叶部则增加.根、叶部各亚细胞组分Cu分布比例呈波动变化,Mn分布比例相对稳定.随胁迫加剧,Cu的迁移表现为“低促高抑”,Mn则呈增加趋势.综上,气候变暖与干旱复合胁迫可在不同层面对小麦幼苗中Cu、Mn元素的动态累积和分布产生不对等影响,最终可能威胁粮食营养供给平衡;结果可为农业系统科学应对气候变化提供理论参考.

Multiple adverse stresses, such as warming and drought caused by global warming, have seriously threatened global food security and human health. In this study, wheat(Triticum aestivum) seedlings were taken as the research object;the effects of combined climate warming and drought stresses were simulated in an artificial climate chamber, and the dynamic accumulation and distribution of Cu and Mn at the subcellular level in wheat seedlings under the combined stress of climate warming and drought were studied. In this study,we aimed to explore the mineral nutrient response dynamics and mechanisms of crops at the subcellular level under multiple stress conditions. The results indicated that with the increase in stress levels, the enrichment of Cu in the roots and leaves of wheat seedlings indicated a significant downward trend;the enrichment of Mn in the roots indicated a downward trend, while that in the leaves indicated an increasing trend. The lowest enrichment coefficients of Cu in roots and leaves decreased to 0.50 and 0.31 times that of the control,respectively;the enrichment coefficient of Mn in roots decreased to 0.70 times that of the control and Mn in leaves increased to 1.40 times that of the control. The Cu content in the subcellular components of roots and leaves of wheat seedlings decreased with an increase in the stress level, and the Mn content in each subcellular component of roots decreased, but increased to different degrees in the leaves. The distribution proportion of Cu in each subcellular layer of the roots and leaves of wheat seedlings fluctuated, and the distribution proportion of Mn remained relatively stable. With the aggravation of stress, the migration of Cu from the roots to the stems and leaves of wheat seedlings increased under mild stress, and decreased under high stress, and the migration of Mn significantly increased. The results demonstrate that the combined climate warming and drought stresses can have unequal effects on the dynamic accumulation and distribution of Cu and Mn in wheat seedlings at different levels, which may eventually threaten the balance of food nutrition supply. The study results provide a theoretical reference for agricultural systems to scientifically deal with climate change.