Transgenic indica rice expressing a bitter melon (Momordica charantia) class I chitinase gene (McCHIT1) confers enhanced resistance to Magnaporthe grisea and Rhizoctonia solani

Eur J Plant Pathol (2009) 125:533543 DOI 10.1007/s10658-009-9501-8

Transgenic indica rice expressing a bitter melon (Momordica charantia) class I chitinase gene (McCHIT1) confers enhanced resistance to Magnaporthe griseaand Rhizoctonia solani

Ping Li & Yan Pei & Xianchun Sang &

Yinghua Ling & Zhenglin Yang & Guanghua He

Received: 24 November 2008 /Accepted: 22 June 2009 /Published online: 5 July 2009 # KNPV 2009

Abstract McCHIT1 chitinase (DQ407723), a class I secretory endochitinase from bitter melon (Momordica charantia), had been demonstrated to enhance resistance against Phytophthora nicotianae and Verticillium wilt in transgenic tobacco and cotton. In order to obtain disease-resistant transgenic rice, McCHIT1 was transformed into a restorer line JinHui35 (Oryza sativa subsp. indica) by using the herbicide-resistance gene Bar as the selection marker. Transgenic rice lines and their progenies overexpressing the McCHIT1 gene showed enhanced resistance to Magnaporthe grisea (rice blast) and Rhizoctonia solani (sheath blight), two major fungal pathogens of rice. McCHIT1-transgenic rice confirmed the inheritance of the transgene and disease resistance to the subsequent generation. The T2 transformants exhibited significantly increased tolerance to M. grisea, with a 30.0 to 85.7 reduction in

disease index, and R. solani, with a 25.0 to 43.0 reduction in disease index, based on that of the control as 100. These results indicated that over-expression of the McCHIT1 gene could lead to partial disease reduction against these two important pathogens in transgenic rice.

Keywords Disease resistance . Indica .

McCHIT1 gene . Blast . Sheath blight

AbbreviationsAS acetosyringoneCaMV35S Cauliflower mosaic virus 35S promoter CIAP calf intestinal alkaline phosphatase GlcNAc N-acetylglucosamineGLU glucanaseGUS -glucuronidaseNPR1 non-expressor of pathogenesis-related genes 1PAL phenylalanine ammonia lyasePMSF pheylmethylsulfonyl fluoridePPT phosphinothricinPR pathogenesis-relatedSAR systemic acquired resistance

Introduction

Blast and sheath blight, seriously affecting yield and quality of rice (Oryza sativa) worldwide, are caused by

P. Li : X. Sang : Y. Ling : Z. Yang : G. He (*) Rice Research Institute,College of Agronomy and Biotechnology, Southwest University,Beibei,Chongqing 400716, Peoples Republic of China e-mail: [email protected]

Y. PeiKey Laboratory of Southwest Crop Genetic Improvement and Breeding, Ministry of Agriculture,Southwest University,Beibei,Chongqing 400716, Peoples Republic of China

534 Eur J Plant Pathol (2009) 125:533543

the fungal pathogens Magnaporthe grisea and Rhizoctonia solani respectively. Usually the control of these fungal pathogens mainly involves three strategies: culture technique, the application of agrochemicals and...