转苋色藜NDR1基因水稻的获得及对白叶枯病抗性的初步研究

NDR1(non-race-specific disease resistance)基因能介导植物广谱抗病,在植物的防御反应中发挥重要作用。以特色抗病植物苋色藜为材料,克隆并鉴定了NDR1的同源基因Ca NDR1a和Ca NDR1b。在此基础上,利用该基因分别构建植物表达载体,农杆菌介导转化法获得转基因水稻,经PCR和Southern杂交证明外源基因已整合到水稻基因组中。选取部分株系进行水稻白叶枯病抗性鉴定,记录接种后3 d、5 d、10 d的叶片病斑长度,结果表明:转Ca NDR1a、Ca NDR1b基因水稻对白叶枯病具有一定的抗性,可延迟发病。外源基因在转基因水稻植株中均有较高水平表达,但抗病性较好株系Ca NDR1基因的表达量并非最高。农艺性状调查结果显示多数转基因植株株高较对照组矮,但结实率、千粒重等农艺性状与对照组相比并无显著差异。

Transgenic Rice with Chenopodium amaranticolor NDR1 Genes and Preliminary Investigation on Bacterial Blight Resistance

NDR1(non-race-specific disease resistance 1) gene can mediate broad-spectrum in plant disease resistance and plays an important role in defense responses. Two NDR1 homologous genes CaNDR1a and CaNDR1b were cloned from Chenopodium amaranticolor, and plant expression vectors were constructed and generated transgenic rice by agrobacteria -mediated transformation, respectively. PCR and Southern blot assay demonstrated that those two genes were integrated into rice genome. Parts of transgenic lines were selected to conduct identification of resistance to rice bacterial leaf blight. The length of leaf disease spot were recorded in 3 d, 5 d, 10 d after inoculation. Results indicated that the expression of CaNDR1a and CaNDR1b in rice had certain resistance to bacterial leaf blight and delayed symptom development of the pathogen. Expression levels of exogenous genes in transgenic rice plants were significantly higher than those of control. However, higher disease resistance line did not show the highest expression results of CaNDR1. There were not significant different with receptor rice in agronomic traits such as seed setting rate and thousand seed weight, besides of shorter plant.