Liu Mei, Sun Zong-xiu, Zhu Jie, Xu Tong, Harman Gary E, Lorito Matteo
College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310029, China.
J Zhejiang Univ Sci. 2004 Feb;5(2):133-6. doi: 10.1007/BF02840913.
Three genes encoding for fungal cell wall degrading enzymes (CWDEs), ech42, nag70 and gluc78 from the biocontrol fungus Trichoderma atroviride were inserted into the binary vector pCAMBIA1305.2 singly and in all possible combinations and transformed to rice plants. More than 1800 independently regenerated plantlets in seven different populations (for each of the three genes and each of the four gene combinations) were obtained. The ech42 gene encoding for an endochitinase increased resistance to sheath blight caused by Rhizoctonia solani, while the exochitinase-encoding gene, nag70, had lesser effect. The expression level of endochitinase but exochitinase was correlated with disease resistance. Nevertheless, exochitinase enhanced the effect of endochitinase on disease resistance when the two genes co-expressed in transgenics. Resistance to Magnaporthe grisea was found in all kinds of regenerated plants including that with single gluc78. A few lines expressing either ech42 or nag70 gene were immune to the disease. Transgenic plants are being tested to further evaluate disease resistance at field level. This is the first report of multiple of expression of genes encoding CWDEs from Trichoderma atroviride that result in resistance to blast and sheath blight in rice.
将生防真菌深绿木霉中编码真菌细胞壁降解酶（CWDEs）的三个基因ech42、nag70和gluc78单独以及以所有可能的组合插入双元载体pCAMBIA1305.2中，并转化到水稻植株中。在七个不同群体（针对三个基因中的每一个以及四个基因组合中的每一个）中获得了1800多个独立再生的植株。编码内切几丁质酶的ech42基因增强了对立枯丝核菌引起的纹枯病的抗性，而编码外切几丁质酶的nag70基因的作用较小。内切几丁质酶而非外切几丁质酶的表达水平与抗病性相关。然而，当这两个基因在转基因植株中共表达时，外切几丁质酶增强了内切几丁质酶对抗病性的影响。在包括单个gluc78在内的所有再生植株中都发现了对稻瘟病菌的抗性。一些表达ech42或nag70基因的株系对该病免疫。正在对转基因植株进行田间试验，以进一步评估其抗病性。这是关于深绿木霉中编码CWDEs的基因多重表达导致水稻对稻瘟病和纹枯病产生抗性的首次报道。
