Arabidopsis IQM1 is involved in stomatal innate immune

【作者】 周玉萍； Qiong-Hua Chen； Xiao-Ling Huang； Zhang-Ke Huang； Zhong-Zhen Mo； 田长恩；

【Author】 Yu-Ping Zhou;Qiong-Hua Chen;Xiao-Ling Huang;Zhang-Ke Huang;Zhong-Zhen Mo;Chang-En Tian;School of life Sciences,Guangzhou University;

【机构】 School of life Sciences,Guangzhou University；

【摘要】 Arabidopsis IQMs share sequence homology with a pea heavy metal-induced protein 6 and a trichosanthin.Distinct expression patterns for each gene suggest that each IQM family member may play a different role in plant development and response to environmental cues.However functions of the IQM family members remain to be analyzed.IQMl can bind with AtCaM5 in yeast two-hybrid assay via its IQ-motif.The CaM binding was Ca-independent in vitro,and was also observed in bimolecular fluorescence complementation analyses in onion epidermal cells.IQMl was found to express strongly in guard cells and the cortex of roots.The T-DNA insertion mutants of IQMl(iqml) displayed a smaller stomatal aperture,a decreased water loss rate and a shorter primary root.Moreover,iqml did not change its stomatal aperture when treated with light,dark,ABA and chitin obviously.Stomatal guard cell of iqml-1 also showed enhanced expression of genes involved in production and signaling of reactive oxygen species(ROS).Consistently,increased ROS level was observed in guard cells.Interestingly,243 and 28 genes were up- and down-regulated by more than two fold in the leaf of iqml-1,respectively.Particularly,34 of 117 and 7 of 30 chitin-responsive transcriptional factor and ubiquitin ligase genes were up-regulated.Furthermore 51defense-associated genes in iqml-1 were also up-regulated.Consistent with above,iqml-1 was found to be more resistant to Pst DC3000 than wild type when the pathogen is sprayed,but to show similar symptom to wild type when the pathogen is infiltrated,suggesting that IQMl is involved in stomatal innate immune.Our further results showed that mutation of IQMl reduces sensitivity to J A which enhances stomatal aperture and consequently reduces resistance to Pst DC3000,indicating that IQMl enhance J A signal transduction and stomatal open and consequently reduce resistance to Pst DC3000.更多还原

【Abstract】 Arabidopsis IQMs share sequence homology with a pea heavy metal-induced protein 6 and a trichosanthin.Distinct expression patterns for each gene suggest that each IQM family member may play a different role in plant development and response to environmental cues.However functions of the IQM family members remain to be analyzed.IQMl can bind with AtCaM5 in yeast two-hybrid assay via its IQ-motif.The CaM binding was Ca-independent in vitro,and was also observed in bimolecular fluorescence complementation analyses in onion epidermal cells.IQMl was found to express strongly in guard cells and the cortex of roots.The T-DNA insertion mutants of IQMl(iqml) displayed a smaller stomatal aperture,a decreased water loss rate and a shorter primary root.Moreover,iqml did not change its stomatal aperture when treated with light,dark,ABA and chitin obviously.Stomatal guard cell of iqml-1 also showed enhanced expression of genes involved in production and signaling of reactive oxygen species(ROS).Consistently,increased ROS level was observed in guard cells.Interestingly,243 and 28 genes were up- and down-regulated by more than two fold in the leaf of iqml-1,respectively.Particularly,34 of 117 and 7 of 30 chitin-responsive transcriptional factor and ubiquitin ligase genes were up-regulated.Furthermore 51defense-associated genes in iqml-1 were also up-regulated.Consistent with above,iqml-1 was found to be more resistant to Pst DC3000 than wild type when the pathogen is sprayed,but to show similar symptom to wild type when the pathogen is infiltrated,suggesting that IQMl is involved in stomatal innate immune.Our further results showed that mutation of IQMl reduces sensitivity to J A which enhances stomatal aperture and consequently reduces resistance to Pst DC3000,indicating that IQMl enhance J A signal transduction and stomatal open and consequently reduce resistance to Pst DC3000.更多还原