Studies On The Effects Of Hormone And Heat Shock On Soybean (Glycine Max (L.) Merrill) Legume Abscission And Its Molecule Mechanism

Soybean flowers and pods abscission is not only the self-regulation of soybean growth and reproduction, but also an important restriction factor of yield. The early stage of soybean anthesis is the sensitivity for legume abscission.The abscission of soybean flowers and pods was effectively reduced when artificial regulation was applied . So there is important academic significance and application value , to carry out research on the abscission of soybean flowers and pods, and its regulation mechanism during the early stage of anthesis.Four soybean varieties the zaoshu 18 (Z18) , Ludou 4 (LD4) , Jinghuang 3 (JH3) and Kefeng 1 (KF1) were used in this research. Study on the change of endohormone content of soybean during its early anthesis stage were conducted with exohormone (IAA,ABA) and heat shock (HS) treatment. Meanwhile, the molecular mechanism of the soybean legume abscission was studied by analysis were used to examine the genie expression of heat shock protein 70 (HSP70) and abscission cellulase (AC) after treatment. Methods such as Northern blotting, physiological and biochemical analysis were used to examine the genie expression of HSP70 and AC, the content of exohormone(IAA,ABA), and the change of legume abscission rate. The main results were shown as follows.1. Heat shock strengthened the genie expression of HSP70, but there was significant difference among the four varieties. The genie expression AC of the four varieties were all reduced by heat shock. There was negatively relationship between HSP70 and AC, the increase of HSP70 content restricted the expression of AC gene. 2.The endohormone ABA contents in the abscission layer of the four varieties were all reduced by heat shock ,but the endohormone IAA contents were significantly increased.3.The HSP70 contents of the most varietiws were increased after treatment with different concentration of IAA alone, and the increase was more obvious when treated with IAA and HS together. The effect on the genie expression of HSP70 of treatment with ABA alone was less than the treatment of ABA and HS together. Results showedthat the AC gene expression was enhanced by ABA and reduced by IAA. The effect of endohormone on legume abscission was great, but there were differences among different concentrations. Legume abscission rate was reduced by lower concentration IAA treatment and increased by ABA treatment, and the abscission was more significantly with increased ABA concentration.4.The way regulating legume abscission might be that the HSP70 regulate the transformation of endohormone, and the endohormone regulate AC, which controlling the legume abscission.