Cloning And Sequence Analysis Of Candidate Gene MSRA Related To Anthracnose Resistance From Stylosanthes Guianensis Mineirao

Stylosanthes spp is a promise tropic leguminous forage, which is native to the middle of South America, North America, Africa, South-east Asia and India. Nowadays, stylo has been planted and popularized widely in the tropical and subtropical regions of South China. But owing to the fact that the emergence and prevalence of stylo anthracnose arised tremendous obstacle to the Stylosanthes utilization. Stylosanthes guianensis cv. Mineirao is a high resistance anthracnose variety and was to planted widely in Brazil, while its anthrancose resistance mechanism is unknown yet. A specific fragment of SG2950-1 has been obtained from genome DNA of Stylosanthes guianensis cv. Mineirao with the technique of AFLP in our laboratory, which is likely to the middle fragment of a candidate gene with resistance to stylo anthracnose.The total RNA from leaves of Stylosanthes was extracted successfully by an improved CTAB method in this paper. And a good method of extract total RNA from leaves of stylosanthes was estabilished. Specific primer was designed based on the fragment of SG2950-1. The complete sequence of cDNA was obtained with methods of RT-PCR and RACE, which contained a open reading frame with 1563bp, and it was named as MSRA gene. There is 64% of homology between the amino acid sequence of cytochrome P450 monooxygenase in Nicotiana tomentosiformis and sequence deduced from MSRA. The protein characters, molecular weight and transmenbrane regions of MSRA gene are similar to that of the cytochrome P450 enzyme. From these rusults, it can imply that MSRA gene is related to the resistance anthracnose. While, the function of MSRA gene need to be tested with the method of plant transformation .