Indica Rice Callus Culture And Characterization Of A Yellow-green Leaf Rice Mutant

Rice is one of the most important food crops, and is also a model plant in monocot species. With the accomplishment of rice genome sequencing project, a new era of functional genomics has arrived in rice genetics research. The main task of rice functional genomics is functional deciphering of rice genes. Currently, several approaches have been developed in rice to clone new genes and determinate their functions, and among these strategies developing mutant population and deciphering functional genes through mutants concerned is most efficient, and mutagenesis through Ac/Ds tagging system is one of the most widely used and efficient tools for producing mutant population. To promote the development of rice functional genomics, in this paper, we will make two researches around rice Ac/Ds transposon tagging system.1. To push the development of Ac/Ds transposon tagging system in indica rice, we have made indica rice mature embryo callus culture and acquired results as follows: (1) The calli of seven varieties, including Jiayu 948, Yanghui 559, Yangxian 6547, Zhongerruanzhan, Minghui 86, Guanghui 998, and Zunxian 3, were best initiated on callus initiation media containing 2,4-D at 0.5 mg/L; The calli of Zhenhui 084 were best initiated on media containing 2,4-D at 1.0 mg/L ; When the level of 2,4-D was set at 1.5 mg/L, the calli of two varieties, including Yangdao 6 and Xianxiaonian, were best initiated; On media containing 2,4-D at 0.5 ~ 2.5 mg/L , the calli of two varieties, including Zhongjian 100 and Xiangwanxian 1, could not be initiated; (2) 0.2 mg/L 6-BA was supplemented into callus initiation media containing optimal 2,4-D level with an objective to explore the effects of 6-BA on callus initiation and plantlet regeneration, and it was found that the 6-BA treatment had no significant effects on callus initiation frequency, but could reduce plantlet regeneration frequency; (3) Not only plantlet regeneration frequency could be maintained and even increased, but also the quality of regenerated plantlets could be improved when the concentration of 6-BA in plantlet regeneration medium was properly reduced.2. We have found a yellow-green leaf mutant in Ds insertion rice lines, and during the genetic study of the mutant, we achieved the following results: (1) Using hiTAIL-PCR, we have established a stable system for identifying Ds flanking sequences; It is indicated that hiTAIL-PCR is more stable and efficient than TAIL-PCR, and can be applied to isolate Ds flanking sequences in genomes with more complexity than rice; (2) The yellow-green leaf mutant is caused by a single recessive mutant; Using hiTAIL-PCR, we isolated the Ds flanking sequence in the mutant, and sequence analysis revealed that the Ds element was inserted 150bp upstream of the rice predicted gene Os03g0344200; Analysis indicated that there is no genetic linkage between the Ds insertion and the yellow-green leaf mutant.