莱茵衣藻活细胞制剂缓解小麦幼苗镉胁迫的效应与机制  

Effect and Mechanism of Chlamydomonas reinhartii Living Cell Agents in Alleviating Cd Stress on Wheat Seedlings

作　　者：雷春燕 李亚男 梁梦静 杨泽 孙岩 季春丽 张春辉 李润植[1] 孙希平[1] 崔红利[2] LEI Chun-yan;LI Ya-nan;LIANG Meng-jing;YANG Ze;SUN Yan;JI Chun-li;ZHANG Chun-hui;LI Run-zhi;SUN Xi-ping;CUI Hong-li(Shanxi Engineering Research Center for Genetics and Metabolism of Special Crops,College of Agriculture,Shanxi Agricultural University,Taigu 030801,China;Key Laboratory of Coastal Biology and Biological Resource Utilization,Yantai Institute of Coastal Zone Research,Chinese Academy of Sciences,Yantai 264003,China)

机构地区：[1]山西农业大学农学院,山西省特用作物遗传与代谢工程研究中心,太谷030801 [2]中国科学院烟台海岸带研究所,海岸带生物学与生物资源利用重点实验室,烟台264003

出　　处：《环境科学》2025年第3期1795-1805,共11页Environmental Science

基　　金：国家重点研发计划项目(2021YFD1901100);省部共建有机旱作农业国家重点实验室(筹)自主研发课题项目(202105D121008-3-6);山西省高等学校科技创新项目(2021L119);山西省农业厅“六新”项目。

摘　　要：重金属镉(Cd)污染不仅导致农作物减产,而且可通过食物链传递和积累,对人类健康构成威胁.减少作物对Cd吸收和富集,以及提高Cd胁迫抗性是绿色健康农业可持续发展的重要议题.为建立应用微藻防控Cd污染和提高作物抗逆性的新农艺技术,选用莱茵衣藻(Chlamydomonas reinhardtii)和小麦(Triticum aestivum)开展系统研究,以期阐明微藻阻滞Cd迁移和增强作物Cd胁迫抗性的效果及作用机制.供试作物为冬小麦品种晋麦182(JM182)和春小麦品种津春6号(JC6).水培试验设置2个剂量的Cd胁迫即50 mg·L^(-1)(Cd50)和100 mg·L^(-1)(Cd100).制备2种剂量的莱茵衣藻活细胞制剂即藻液D_(680)为1.0(A1.0)和D_(680)为2.0(A2.0).测定小麦幼苗生长、生理响应、Cd吸收、转运和积累,以及重金属转运相关基因转录表达等参数.结果表明,Cd胁迫严重抑制小麦幼苗生长.施用莱茵衣藻活细胞制剂可显著增加小麦幼苗光合色素含量和激活抗氧化酶系统活性,显著减轻Cd胁迫对小麦幼苗的伤害.此外,莱茵衣藻活细胞制剂A1.0和A2.0处理均能下调小麦幼苗重金属吸收和转运相关基因(TaHMA2、TaHMA3、TaNramp1和TaLCT1)的转录表达.小麦幼苗Cd含量测定显示,Cd50和Cd100胁迫分别导致JC6春小麦幼苗Cd富集量达185.01mg·kg^(-1)和342.11 mg·kg^(-1),Cd在JM182冬小麦幼苗积累量达176.76 mg·kg^(-1)和317.65 mg·kg^(-1).显然,与JM182品种相比,JC6小麦品种易于吸收和富集Cd.重要的是,微藻活细胞制剂处理则显著减少2个品种小麦幼苗Cd积累量.与Cd50处理的JC6品种小麦幼苗相比,A2.0处理的JC6品种小麦幼苗根部和茎叶部的Cd积累量分别下降了76.80%和66.91%,且Cd从根部向茎叶部转移率减低了27.58%.结果显示,莱茵衣藻活细胞制剂通过调控重金属吸收和转运相关基因的表达,显著减少小麦幼苗对Cd的吸收和从根部向茎叶器官的转运与积累.莱茵衣藻活细胞制剂亦可通过激活抗氧化系统�Cadmium(Cd)pollution not only leads to the reduction in crop yields but also migrates and accumulates through the food chain,thus posing a threat to human health.It is an important issue to reduce Cd uptake and enrichment in crops and increase crop resistance to Cd stress for sustainable development of green-health agriculture.To establish a novel agronomic technique using microalgae to control Cd pollution and improve crop stress resistance,the microalga Chlamydomonas reinhardtii and wheat(Triticum aestivum)were employed for systematic investigation so as to the elucidate effects and mechanism of microalgae in blocking Cd migration and enhancing crop resistance to Cd stress.The test crop materials were the winter wheat variety JM182 and spring wheat variety JC6.Hydroponic experiments were used to simulate Cd stress at two dosages,50 mg·L^(−1)(Cd50)and 100 mg·L^(−1)(Cd100).Two different dosages of C.reinhardtii living cell agents,i.e.,the microalgal cell cultures with D_(680)=1.0(A1.0)and D_(680)=2.0(A2.0),were prepared using conventional microalgal-cultivation methods and subsequently used to treat wheat seedlings under Cd stress.Several physiological and biochemical parameters were determined for wheat seedlings under two doses of Cd stress,respectively,including growth features,photosynthesis,cellular antioxidant enzyme activity,Cd uptake,transportation and accumulation,and transcriptions of the genes associated with heavy metal transportation.The results showed that Cd stress crucially inhibited the growth of wheat seedlings.However,the application of C.reinhardtii living cell agents significantly increased the contents of photosynthetic pigments(chlorophyll a,chlorophyll b,and carotenoids)and activated the antioxidant enzyme system activities(SOD,POD,CAT,GSH,and APX).The microalgal living cell agents also reduced the damage of Cd stress on wheat seedling growth.Moreover,both doses(A1.0 and A2.0)of C.reinhardtii living cell agents downregulated the expression of the genes related to heavy metal absorpti

关 键 词：镉(Cd)胁迫 小麦幼苗 微藻活细胞制剂 抗氧化系统 光合作用 重金属吸收和积累 

分 类 号：X171.5[环境科学与工程—环境科学]