The LysM Receptor-Like Kinase LysM RLK1 Is Required to Activate Defense and Abiotic-Stress Responses Induced by Overexpression of Fungal Chitinases in Arabidopsis Plants  

作　　者：Yariv Brotman Udi Landau Smadar Pnini Jan Lisec Salma Balazadeh Bernd Mueller-Roeber Aviah Zilberstein Lothar Willmitzer Ilan Chet Ada Viterbo 

机构地区：[1]Genes and Small Molecules, AG Willmitzer, Max-Planck-lnstitut of Molecular Plant Physiology, Am Muhlenberg 1, D-14476 Potsdam-Golm, Germany [2]Department of Plant Pathology and Microbiology, The Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel [3]Department of Plant Science, Tel Aviv University, Tel Aviv 69978, Israel [4]University of Potsdam, Institute of Biochemistry and Biology, KarI-Liebknecht-Strae 24-25, Haus 20, 14476 Potsdam-Golrn, Germany

出　　处：《Molecular Plant》2012年第5期1113-1124,共12页分子植物（英文版）

摘　　要：Application of crab shell chitin or pentamer chitin oligosaccharide to Arabidopsis seedlings increased toler- ance to salinity in wild-type but not in knockout mutants of the LysM Receptor-Like Kinasel （CERK1/LysM RLK1） gene, known to play a critical role in signaling defense responses induced by exogenous chitin. Arabidopsis plants overexpress- ing the endochitinase chit36 and hexoaminidase excyl genes from the fungus Trichoderma asperelleoides T203 showed increased tolerance to salinity, heavy-metal stresses, and Botrytis cinerea infection. Resistant lines, overexpressing fungal chitinases at different levels, were outcrossed to lysm rlkl mutants. Independent homozygous hybrids lost resistance to biotic and abiotic stresses, despite enhanced chitinase activity. Expression analysis of 270 stress-related genes, including those induced by reactive oxygen species （ROS） and chitin, revealed constant up-regulation （at least twofold） of 10 genes in the chitinase-overexpressing line and an additional 76 salt-induced genes whose expression was not elevated in the lysm rlkl knockout mutant or the hybrids harboring the mutation. These findings elucidate that chitin-induced signaling mediated by LysM RLK1 receptor is not limited to biotic stress response but also encompasses abiotic-stress signaling and can be conveyed by ectopic expression of chitinases in plants.Application of crab shell chitin or pentamer chitin oligosaccharide to Arabidopsis seedlings increased toler- ance to salinity in wild-type but not in knockout mutants of the LysM Receptor-Like Kinasel （CERK1/LysM RLK1） gene, known to play a critical role in signaling defense responses induced by exogenous chitin. Arabidopsis plants overexpress- ing the endochitinase chit36 and hexoaminidase excyl genes from the fungus Trichoderma asperelleoides T203 showed increased tolerance to salinity, heavy-metal stresses, and Botrytis cinerea infection. Resistant lines, overexpressing fungal chitinases at different levels, were outcrossed to lysm rlkl mutants. Independent homozygous hybrids lost resistance to biotic and abiotic stresses, despite enhanced chitinase activity. Expression analysis of 270 stress-related genes, including those induced by reactive oxygen species （ROS） and chitin, revealed constant up-regulation （at least twofold） of 10 genes in the chitinase-overexpressing line and an additional 76 salt-induced genes whose expression was not elevated in the lysm rlkl knockout mutant or the hybrids harboring the mutation. These findings elucidate that chitin-induced signaling mediated by LysM RLK1 receptor is not limited to biotic stress response but also encompasses abiotic-stress signaling and can be conveyed by ectopic expression of chitinases in plants.

关 键 词：abiotic stress chitin-induced signaling CHITINASES LysM receptor kinase Trichoderma. 

分 类 号：S476[农业科学—农业昆虫与害虫防治] Q945.78[农业科学—植物保护]