Screening Of Mutants With Chloroplast Accumulating In Vascular Bundle Sheath Cell And Identification Of Them In Rice

Rice is the most important crop in our country.Breeding for high photosynthesis efficiency has become a hot topic in the world.Traditional method has not been able to effectively increase the rice yield,and transferring C4 gene into rice is not perfect enough.Many experiments have confirmed the existence of C4 channels that in C3 plants,and it is an ideal method to screen the C4-like mutants in C3 plants.(1)10 variant lines of chloroplast accumulating in vascular bundle sheath cell were screened from 8 600 strains in rice.(2)The results showed that the yield of mutants decreased,the plant height decreased and the seed setting rate decreased.At the seedling stage,the chlorophyll content of mutant was higher than that of wild type,and the gap gradually decreased at tillering stage and mature stage.The photosynthetic rate,stomatal conductance and transpiration rate of the wild type were significantly higher than those of the mutants,the intercellular CO2 concentration was lower.the overall growth status of the mutants was weaker than the wild type,and the light response curve indicated that the photosynthetic rate,The light saturation point of the mutants was higher than that of the wild type,and the respiration of mutants was weaker than the wild type.PEPCase and RuBPase activity measurements showed that the PEPCase activity of the mutants was generally increased and the activity of RuBPase was decreased.Soluble protein content also decreased in the mutants.(3)Three effective T-DNA insertion sites were obtained by Tail-PCR,and three possible functional genes(Os7g23530,Os09g15820,Os09g15810)were predicted in the range of 12 000 bp insertion site.