Mapping And Preliminary Functional Analysing Of A Thermo-sensitive Seedling Leaf-color Mutant (tsl11) In Rice

Leaf-color mutants were a common mutant in rice, and it played a very important role in the study of rice functional genomics. At present, although many leaf-color mutants have been found in rice,few genes have been cloned.Moreover,these cloned genes’ fuction and regulation hadn’t been studied clearly. These results showed that the potential of study leaf-color mutant is huge. Therefore, if strengthens the study of rice leaf-color genes’ fuction and regulation, it had significance on applying and revealing the mechanism of photosynthesis. In this paper, through map-cloning and preliminary analysis of a new thermo-sensitive leaf color mutant(tsl11),the main results were summarized as follows:1. the thermo-sensitive of tsl11:under24℃the3rd and4th leaves showed etiolation, but the leaf-colour will back to normal after the5th leaf stage. However, the leaf colour of mutant leaves were similar to the wild type at32℃.2. Under20℃,compared with the wild type,the contents of photosynthetic pigment declined significantly; while at32℃, there was almost no difference between tsl11and Jiahua NO.1. At20℃,mutant plants had much fewer and smaller undifferentiated chloroplasts compared with wild-type plants.There were no differences found between wild-type and mutant plants in sizes or numbers of chloroplasts under32℃. The investigation of the agronomic characters:compared with the wild type, the plant height and SPAD value of tsl11were decline before four-week seedling.In addition, panicle length,panicle number and1000-grain-weight were also decline.3. Genetic analysis showed that the mutant trait was controlled by a single nuclear recessive gene, tentatively designated as tsl11. Moreover, the mapping population of4928F2mutant-type plants derived from Pei’ai64S/tsl11was constructed, then using SSR and InDel markers, the tsl11gene was finally mapped to a region of147kb between ID14506and ID14653on chromosome11. DNA sequence analysis found two bases delete in regulatory sequence of LOC-Os11g26150,which resulted a premature termination transcription. 4. We also detected the expression level of TSL11and the expression of some chlorophyll synthesis and chloroplast development associated genes in the mutant and wild type plant.the results showed that the expression of TSL11was up-regulated in the mutant type under low temperature, but under high temperature the expression of TSL11is similar to wide type; and TSL11might be directly regulate the early development process of chloroplasts. Moreover, the mRNA expression of tsl11analysis showed TSL11was a constitutive gene,existed the higher expression in leaf than other tissue.Our research discovered a novel thermo-sensitive leaf color mutant gene in rice,TSL11, the fuction of tsl11had been analysed briefly. These results in this study would in favour of the further gene functions, and provide help to us for the further study on early temperature molecular mechanism of regulation of chloroplast development.