外源褪黑素对铬(Cr^(6+))胁迫下小麦幼苗光合特性和养分吸收的影响  

Effects of Exogenous Melatonin on Photosynthetic Characteristics and Nutrient Absorption of Wheat Seedlings under Cr^(6+)Stress

作　　者：孙传蛟 谭清文 刘晓雪[1] 张紫刚 孙建云[2] SUN Chuanjiao;TAN Qingwen;LIU Xiaoxue;ZHANG Zigang;SUN Jianyun(l.College of Agriculture,Nanjing Agricultural University,Key Laboratory of Crop Physiology Ecology and Production Management of Ministry of Agricultural,Nanjing,Jiangsu 210095,China;College of Life Science,Nanjing Agricultural University,Nanjing,Jiangsu 210095,China)

机构地区：[1]南京农业大学农学院,农业农村部作物生理生态与生产管理重点实验室,江苏南京210095 [2]南京农业大学生科院,江苏南京210095

出　　处：《麦类作物学报》2022年第12期1535-1542,共8页Journal of Triticeae Crops

基　　金：国家重点研发计划项目(2017YFD0301204)。

摘　　要：为明确褪黑素对铬(Cr^(6+))胁迫下小麦幼苗光合和养分吸收的调节作用,在水培条件下以豫麦51(铬敏感型)和扬麦16(耐铬型)为材料,分析了Cr^(6+)胁迫下外源褪黑素预处理(100μmmol·L^(-1))后小麦幼苗光合和荧光参数及养分含量的变化。结果表明,Cr^(6+)胁迫显著降低了小麦叶片叶绿素含量、气孔导度(Gs)和光系统Ⅱ(PSⅡ)活性,导致光合速率(Pn)显著降低;Cr^(6+)胁迫也显著减弱了根系对营养元素(N、P、K、Mg、Fe和Mn)的吸收和转运。外源褪黑素处理显著提高了Cr^(6+)胁迫下小麦幼苗的P_(n)、G_(s)、叶绿素(a和b)含量、实际光化学效率(ΦPSⅡ)、最大光化学效率(F_(v)/F_(m))、光化学淬灭(qL)和电子传递能力(ETR),增加了根系和叶片营养元素的含量。综合来看,外源褪黑素会促进Cr^(6+)胁迫下小麦幼苗对养分的吸收与转运、气孔开放、CO_(2)传导、光能吸收和电子传递,从而缓解Cr^(6+)对于小麦幼苗光合的抑制作用。To explore the beneficial effect of melatonin on photosynthesis of wheat seedlings under Cr^(6+)stress,Yumai 51(Cr-sensitive)and Yangmai 16(Cr-resistant)were used as the experimental materials in this study.The effects of exogenous melatonin pretreatment(100μmmol·L^(-1)melatonin)on the changes of photosynthetic characteristics and nutrient absorption of wheat seedlings under Cr^(6+)stress were studied through hydroponic method.The results showed that Cr^(6+)stress significantly reduced chlorophyll content,stomatal conductance(G_(s))photosystemⅡactivity,ultimately resulting significant reduction of net photosynthetic rate(P_(n)).Besides,Cr^(6+)stress significantly reduced the uptake and transport of nutrient elements(N,P,K,Mg,Fe,and Mn)in roots.However,exogenous melatonin pretreatment significantly increased the P_(n),G_(s),chlorophyll content,actual photochemical efficiency(ΦPSⅡ),maximum photochemical efficiency(F_(v)/F_(m)),photochemical quenching(qL),electron transport rate(ETR),and nutrient element contents in roots and leaves of wheat seedlings under Cr^(6+)stress.Therefore,exogenous melatonin pretreatment can improve the nutrient absorption and transport capacity,stomatal opening and CO_(2)conduction capacity,light energy absorption and electron transport capacity of wheat seedlings under Cr^(6+)stress,and thus alleviate the inhibition of photosynthesis of wheat seedlings under Cr^(6+)stress.

关 键 词：小麦 铬(Cr^(6+))胁迫 褪黑素 光合特性 叶绿素荧光 养分吸收 

分 类 号：S512.1[农业科学—作物学] S311