Function,Mechnism And Mediation Of Tomato Autophagy In Resisitant To Heat Shock

Tomato (Solanum lycopersicum) is one of the major crops worldwide and plays an important role in agricultural production and consumption. However, the growth and development of tomato are gradually affected with the intensification of greenhouse effect. The normal pollination and fertilization are influenced under high temperature and reduce the yield and quality of tomato. Therefore, it is important to understand the damage and adaptation to high temperature of tomato for exploring more ways to enhance the ability to resist heat injury of tomato and providing effective measures for agriculture production. The study uses non-hybrid tomato varieties Condin Red by analyzing photosynthesis, gene expression, protein changes and phages change with chemical genetics, physiology and molecular biology to study the resistance function and mechanism of autophagy and the role of WRKY33in the regulation of autophagy in response to the high temperature. The following are the major results:1.Studying the important role of autophagy in tomato resistance to high temperature. The high temperature significantly increased the expression of autophagy gene ATG5and ATG7. When ATG5and ATG7was silenced respectively, the capability of plant resistance to high temperature significantly decreased, cell membrane was destructed, photosynthetic system Ⅱ (PS Ⅱ) serious injured, gas exchange was affected and the self-recovery capabilities of photosynthetic system declined. Therefore, autophagy could protect the membrane structure and photosynthetic systems to resist high temperature injury.2.Studying the role of selective autophagy in tomato resistance to high temperature. After NBR1, a receptor of selective autophagy, was dysfunctional, the plants on the high-temperature reaction was consistent with ATG5and ATG7silenced plants and the amount of change of the parameters, such as EL, Pn. Gs, Ci were similar to ATGs silenced plants, indicating NBR1played important roles in the macrophages thermal pathway. UBA1and UBA2were significantly inhibited in ATG5and ATG7silenced plants under high temperature. Meanwhile, ATG5and ATG7 expressions did not up-regulate in UBA1and UBA2silenced plants, indicating that there ws a close connection between autophagic components and NBR1.3.Studying the regulation of WRKY33in tomato autophagy pathway under high temperature. The WRKY33silenced plants became more sensitive to heat and the change of soluble protein content was consistent with ATG silenced plants. The expression of ATG5and ATG7was severely inhibited after WRKY33was suppressed. Autophagosome of WRKY33and ATG5, ATG7silenced plants were much less than control under high temperature. Therefore, as a transcription factor, WRKY33involved in the regulation of tomato autophagy in the upstream of thermal pathway.