5-ALA对干旱胁迫下小麦幼苗光合作用及D1蛋白的调节作用  

Regulation of Exogenous 5-Aminolevulinic Acid on Photosynthesis and D1 Protein of Wheat Seedlings under Drought Stress

作　　者：王嘉楠 李小艳 魏石美 赵会杰[1] 赵明奇 汪月霞[1] Wang Jianan;Li Xiaoyan;Wei Shimei;Zhao Huijie;Zhao Mingqi;Wang Yuexia(College of Life Sciences,Henan Agricultural University,Zhengzhou 450002,Henan,China)

机构地区：[1]河南农业大学生命科学学院,河南郑州450002

出　　处：《作物杂志》2018年第5期121-126,共6页Crops

基　　金：国家自然科学基金-河南联合基金(U1704103);河南省教育厅科学技术研究重点项目(16A210030);河南农业大学科技创新基金项目(KJCX2016A06);全国大学生创新计划项目(201710466013)

摘　　要：为了探究5-氨基乙酰丙酸(5-aminolevulinic acid,5-ALA)对干旱胁迫下小麦幼苗光合作用损伤的缓解机制,选用矮抗58小麦品种为试验材料,在两叶一心期对叶片喷施浓度为100mg/L的5-ALA,处理3d后对根部施加20%聚乙二醇6000(PEG-6000)模拟干旱环境,2d后取样进行光合以及psbA基因表达分析和D1蛋白含量测定。结果表明,干旱胁迫明显降低了小麦叶片的相对含水量以及叶绿素含量,而喷施外源5-ALA能够明显缓解干旱造成的伤害,同时也减缓了干旱胁迫下小麦幼苗净光合速率(P_n)、实际光化学效率(Φ_(PSⅡ))、原初光化学效率(F_v/F_m)和光化学猝灭系数(q_P)值的降低,以及非光化学猝灭系数(q_N)值的升高,并且提高了psbA基因表达水平和D1蛋白的含量。以上结果显示,喷施外源5-ALA可缓解干旱胁迫下小麦幼苗的光合性能,同时诱导psbA基因表达水平提高,加快新D1蛋白的合成与受损D1蛋白的降解,从而提高小麦幼苗的干旱胁迫耐受性。The objectives of this study were to elucidate the alleviation mechanism of exogenous 5-aminolevulinic acid（5-ALA） on the damage of wheat seedlings exposed to drought stress. The Aikang 58 wheat seedlings with two fully expanded leaves were used as the experimental materials. Three days after foliar application of 100 mg/L 5-ALA, 20% polyethylene glycol 6000（PEG-6000） was treated on the root to simulate the drought stress, followed by the photosynthetic physiological and biochemical characteristics and psbA gene expression analysis. The result showed that drought stress significantly decreased the relative water content and the chlorophyll content in wheat leaves. The pre-treatment of 5-ALA could obviously alleviate the injury caused by drought stress, inhibiting the decrease of net photosynthetic rate（Pn）, actual photochemical efficiency（Φ（PSⅡ））, primary photochemical efficiency（Fv/Fm） and photochemical quenching coefficient（qP） values, as well as retarding the increase of non-photochemical quenching coefficient（qN） value. Meanwhile, the transcription of psbA gene and D1 protein content under drought stress were also improved by ALA pre-treatment. The present results proposed that the exogenous application of 5-ALA played a positive regulatory role in the photosynthetic rate and improved the expression level of psbA gene of wheat seedlings under the drought stress, thus accelerated the turnover of the damaged D1 protein and inhibits the degradation of chlorophyll in wheat leaves, which was the benefit of promoting wheat photosynthesis, thereby alleviating the damages caused by drought stress damages on wheat seedling.

关 键 词：小麦 光合作用 5-氨基乙酰丙酸 PSBA基因 D1蛋白 PSⅡ 叶绿素荧光参数 

分 类 号：S512.1[农业科学—作物学]