模拟气候变暖对小麦幼苗亚细胞中Cd的动态累积的影响

Influence of simulated climate warming on Cd accumulation dynamics in subcellular compartments of Triticum aestivum L.

采用气候变暖模拟实验,在高浓度Cd胁迫下,研究模拟温度与CO_2浓度联合升高对小麦幼苗亚细胞中Cd的动态累积的影响,该研究旨在探索全球气候变暖背景下,作物对毒性元素Cd胁迫的微观响应过程及其机制.研究显示,随处理温度和CO_2浓度的增加,根、叶部的富集系数(BF)总体呈现显著的上升趋势,叶部相比对照增加了1.98—3.37倍,根部增加1.90—2.48倍.根、叶部各亚细胞组分中的Cd浓度也呈现显著的增加趋势,但各组分中的Cd相对比例维持稳定,细胞可溶性组分占比最高,是Cd在小麦幼苗细胞中的主要贮存位点.在最高处理温度和CO_2浓度条件下,Cd自根部向叶部的迁移相对对照增加1.34倍.结果表明,气候变暖将在一定程度上影响Cd在小麦幼苗中的动态富集,这很可能在多个层面上进一步强化气候变暖对生态系统、人类食品安全等方面的负性效应.

A simulated climate warming experiment was conducted to evaluate the combined effects of elevated temperature and CO2 concentration on the bioaccumulation of Cd in wheat seedlings. The aim of this study was to explore the process and the mechanism of the crop responses to the stress of Cd in future climate scenarios. The results showed that compared to control,elevated temperature and CO2 increased Cd bioaccumulation factor by 1. 98—3. 37 times in the shoots,by 1. 90—2.48 times in the roots. Moreover,Cd concentration was also significantly increased with the increase of temperature and CO2 concentration in subcellular compartments of roots and shoots of wheat seedlings. The largest proportion of Cd was found in the soluble fractions which were the main storage site for Cd in wheat seedling cells. The increase of temperature and CO2 had no significant effect on the proportional distribution of Cd in the subcellular fractions. In addition,the root- to- shoot translocation of Cd increased significantly under the highest temperature and CO2 treatment conditions. It is likely to further strengthen the negative effects of climate warming on ecosystem,human food security and other aspects on multiple levels.