外源赤霉素调控胡椒花穗形成及增产机理

花穗数目是影响胡椒产量的关键因素之一,前人研究发现喷施赤霉素可以增加胡椒花穗数目,但是增穗机理尚不明确.为了揭示赤霉素调控植物由营养生长向生殖生长转变的机理,选用幼龄胡椒为试材,设置不同浓度赤霉素(20、40、60、100 mg/L)和赤霉素抑制剂多效唑(1500 mg/L),以清水为对照,进行喷施试验.研究测定胡椒的...     

海藻糖对盐胁迫下两个沙棘品种逆境生理的影响

摘要： 通过研究海藻糖对沙棘逆境生理指标的影响规律,探索海藻糖的抗盐生理机制,为生产中应用海藻糖缓解沙棘 盐胁迫提供理论依据 。试验在盆栽条件下,设置空白对照、盐胁迫 + 不同浓度的海藻糖(0、0.2、0.4、0.6 mmol·L-1 )共计 5个处理,3次重复 。结果表明:0.4 mmol·L-1 的海藻糖可以显著提高盐胁迫下两个沙棘品种叶片内的叶绿素、游离脯氨 酸含量,降低 MDA含量;海藻糖会提高盐胁迫下两个品种沙棘叶片内海藻糖-6-磷酸磷酸酶(TPP)活性,提高可溶性糖和可 溶性蛋白含量;0.4mmol·L-1 的海藻糖对提高 TPP活性效果优于0.2mmol·L-1和 0.6mmol·L-1处理,有利于可溶性糖的 积累,缓解盐胁迫对沙棘的危害 。海藻糖对 TPP活性的调控作用可能是其缓解沙棘盐胁迫的生理机制,0.4 mmol·L-1 为适 宜的喷施浓度。     

Three Genes Related to Trehalose Metabolism Affect Sclerotial Development of Rhizoctonia solani AG-1 IA,Causal Agent of Rice Sheath Blight

Trehalose metabolism is related to the sclerotial development of Rhizoctonia solani AG-1 IA, the causal agent of rice sheath blight (RSB). Here, we further elucidated the functions of three genes Rstre, Rstps1 and Rstpp that encode three key enzymes trehalase (TRE), alpha, alpha-trehalose- phosphate synthase (TPS1) and trehalose 6-phosphate phosphatase (TPP) in the sclerotial development of R. solani AG-1 IA. Due to the lack of a stable genetic transformation system for R. solani, the heterologous expression of these three genes in Pichia pastoris GS115 was performed. The results showed that reactive oxygen species (ROS) contents and enzyme activities in R. solani decreased significantly in the treatments of the fermentation broths of Rstps1 and Rstpp transformants, and that in the treatment of the fermentation broth of Rstre transformant visibly increased. Furthermore, the fermentation broths of the transformants of all the three genes were added to potato dextrose agar (PDA) medium for the cultivation of R. solani, as a result, the dry weight of sclerotia in each PDA plate containing the fermentation broths of Rstps1 and Rstpp transformants significantly increased compared with the control, and that of Rstre transformant obviously decreased. Finally, 178 proteins were found to interact with RSTPS1, and 16 of them were associated with ROS. Taken together, the findings suggest that all these three genes related to trehalose metabolism play important roles in the sclerotial development of R. solani AG-1 IA, and can be used as new targets for the development of novel high-efficiency fungicides for the controlling of RSB.