Resistance Analysis Of Lipoxygenase Gene Lox2 Transgenic Rice To Magnaporthe Grisea

It is generally accepted that the Lipoxygenase (LOX) pathway has been deeply involved in the plant defense responses in several aspects: LOX - derived jasmonic acid is relevant to the signal transduction of plant defense responses; other derivative fatty acid oxidized compounds, such as aldehydes and divinylethers (colneleic acid and colnelenic acid) showed antimicrobial activity. Hence, the LOX pathway might play important role in host - pathogen recognition, signal transduction and transcription, and the consequent defense response regulatory.The objective of this study is to investigate the function and role of transgenic Lox2 defense gene and provide useful information to the genetic modification of rice. The analysis of T₁ generation resistance showed the insertion of 35S:: Lox2, 35S::anti Lax2 And 35S::hairpin Loxl structures influenced the resistant and susceptible properties of rice. Through inoculating compatible Magnaporthe grisea 007-2S , 21 out of 54 strains obtained resistance. 9 out of 30 and 2 out of 8 strains became susceptible to Magnaporthe grisea P131-2A and Magnaporthe grisea P131-2H. Meanwhile, most of those susceptible strains obtained hygromycin resistance. The analysis of T₂ generation resistance found 41 out of 54 strains obtained resistance to 007-2S and 2 out of 30 strains become susceptible to P131-2A. Although the results in this study suggested the certain effects of Lox2 gene in the rice defense against Magnaporthe grisea, further study will be needed.The different inserted site and copy number of Lox2 gene showed the transgenic plants come from different independenced transgenic affairs. Besides gene mutation that suggested by the dwarf of 2S-58 and 2S-59 strains, the plant growth increases after application of GA, and leave rust of 2H-16, 2H-18 during the later stage of growth was also found in this study.