低氮诱导小麦灌浆期旗叶衰老与膜脂的关系  

Relationship between Lipid and Flag Leaf Senescence Induced by Low Nitrogen Stress during Grain Filling of Wheat

作　　者：李倩 齐凌云[3,4] 殷俐娜 王仕稳[1,2,3,4] 邓西平 LI Qian;QI Ling-Yun;YIN Li-Na;WANG Shi-Wen;DENG Xi-Ping(College of Natural Resources and Environment,University of Chinese Academy of ciences,Beijing 100049,China;State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau / Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resource,Yangling 712100,Shaanxi,China;Institute of Soil and Water Conservation,College of Life Science,Northwest A＆F University,Yang-ling 712100,Shaanxi,China;College of Natural Resources and Environment,Northwest A＆F University,Yangling 712100,Shaanxi,China)

机构地区：[1]中国科学院大学资源与环境学院,北京100049 [2]中国科学院水利部水土保持研究所/黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100 [3]西北农林科技大学资源环境学院,陕西杨凌712100 [4]西北农林科技大学水土保持研究所,陕西杨凌712100

出　　处：《作物学报》2018年第8期1221-1228,共8页Acta Agronomica Sinica

基　　金：国家自然科学基金项目(31200206);国家科技支撑计划项目(2015BAD22B01);陕西省科技新星项目(2016KJXX-66);中国科学院青年创新促进会项目(2015389)资助~~

摘　　要：小麦产量主要来自于小麦灌浆期旗叶的光合产物,低氮造成的灌浆期旗叶早衰对小麦产量影响极大。本试验以小麦品种"长旱58"为试验材料,在大田环境下设置低氮(120 kg hm^(-2))和正常氮(180 kg hm^(-2))处理,研究低氮诱导的小麦旗叶衰老与膜脂的关系。结果表明,开花14 d后,低氮处理小麦旗叶的光合速率、叶绿素含量、旗叶总氮含量均显著降低;旗叶中膜脂各组分含量均显著下降,DGDG/MGDG的比值升高;以C18:3、C18:2为代表的不饱和脂肪酸含量显著下降,以C16:0为代表的饱和脂肪酸含量显著增加,不饱和双键指数显著降低;此外类囊体蛋白质堆积密度也显著降低。综合分析认为低氮处理导致小麦灌浆期旗叶早衰,早衰过程伴随着膜脂降解和组分改变,降低了膜的流动性和通透性,导致叶绿素降解,使光合功能受损。同时,植物通过调整DGDG/MGDG比例来响应低氮胁迫,利用DGDG的双层特性来部分弥补其它双层膜脂的降解对膜功能造成的损伤。Nitrogen （N） deficiency induces flag leaf senescence at the grain-filling stage of wheat resulting in yield decrease. In this study, we carried out a field experiment to investigate the relationship between N-deficiency-induced flag leaf senescence and lipid change using wheat variety ‘Changhan 58’. Under the low-N （120 kg ha–1） condition, the photosynthetic rate, chlorophyll content, total N content, and contents of all lipid components of flag leaf at 14 days after flowering were significantly lower than those under normal-N （180 kg ha–1） condition, while the DGDG/MGDG ratio in low-N treatment increased. The content of un-saturated fatty acids, such as C18：3 and C18：2 decreased significantly, whereas the contents of saturated fatty acids, such as C16：0, increased significantly, leading to the reduction of index of unsaturated double bounds. In addition, thylakoid protein packing density also decreased under N-deficiency condition. These results indicate that N-deficiency-induced leaf senescence is charac-terized with lipid degradation and components changes, which result in negative effects on reductions of membrane permeability, chlorophyll content and photosynthetic rate. Simultaneously, the DGDG/MGDG ratio of plants is adjusted in response to N defi-ciency to alleviate damages of membrane function caused bby lipid degradation.

关 键 词：小麦 旗叶 低氮 膜脂 衰老 

分 类 号：S512.1[农业科学—作物学]