Autophagy Related Gene OsATG7 Function Research In Rice

Autophagy is a highly conserved process for the turnover of cytoplasmic components in eukaryotes. As a dicotyledonous model plant, Arabidopsis thaliana has won multiple autophagy related gene mutant. Meanwhile, related functions of these genes also have been studied. As a kind of endogen model plant, rice has won very few mutants and the related research of these mutants is still in its infancy. In this paper, mutant of autophagy related gene OsATG7 in rice has been studied.By observing the phenotype of OsATG7 mutants, it has been proved that OsATG7 is closely related to fertility of rice, the homozygous transgenic mutants can be normal heading and flowering but can’t develop seeds, while the heterozygous transgenic plants and negative plants can be normal fructification。By conducting dark treatment to OsATG7 mutants, we found that the autophagy can’t be formed in the homozygous transgenic mutants,but it can be formed in the negative plants induced by dark treatment,it suggests that the lack of Os ATG7 makes rice cannot produce autography. When conducting dark treatment to negative plants, it can induce the increase expression of OsATG7, and degree of increase expression increase with processing time extend, this suggests that autophagy can resist the abiotic stress effect to rice.We observed in the condition of darkness stress, OsATG7 homozygous transgenic mutants show the time of dark treating accelerates the yellowing of leaves, while in heterozygous transgenic plants, the phenomenon of leaves yellowing is not obvious as homozygous transgenic mutants. We did further test of chlorophyll change under the condition of dark stress in three genotypes plants, the result suggests that the loss of chlorophyll in homozygous transgenic mutant is faster than in heterozygous transgenic plant and negative plant. In this experiment, we chose an aging related gene(SGR gene) as a marker to detect the degree of leaf senescence, the result suggests that SGR gene in homozygous transgenic mutants increased quickly with dark stress time increasing, while in heterozygous transgenic plants and negative plants,the SGR gene increased slowly, it explains that in late period of darkness stress, the phenomenon of premature aging happens in homozygous transgenic mutant of rice. Besides,we found that the lack of OsATG7 can result in infertility of rice.When growing in the callus medium and callus subculture medium, the callus formed in Osatg7 homozygous transgenic mutant became browning, while the heterozygous transgenic plants and negative plants can form loose, flaxen and healthy callus,it suggests that the lack of OsATG7 can affect callus formation of rice.