γ-氨基丁酸对烟草MAPK和ACS1基因表达的分叉调节

Bifurcate Regulation of MAPK and ACS1 Gene Expression by γ-Aminobutyric Acid in Nicotiana tabacum

为探讨γ-氨基丁酸（GABA）在植物生长发育中的调控机理,以含有3种不同浓度的GABA的1/2MS培养基培养烟草（Nicotiana tabacum）品种‘SR1’种子,结果表明：低浓度GABA（1mmol/L）促进了烟草幼苗的生长,主根的长度比对照高30%,同时该浓度处理提高了MAPK基因的表达水平;较高浓度（10～100mmol/L）GABA抑制了主根的伸长,表现出乙烯反应的效应。在叶和根中,ACS1基因表达水平的提高受不同浓度GABA的调节。MAPK和ACS1基因对GABA信号的不同表达模式可能与不同的信号途径有关。

ment, the To understand the mechanism of γ-aminobutyric acid （GABA） in plant growth and developseedlings of Nicotiana tabacum （SR1） were cultured in 1/2 MS medium plus three different GABA concentrations. The results showed that GABA can stimulate the growth of Nicotiana tabacum seedlings at a low concentration （1mmol/L）, and the length of primary roots is significant longer than that of the control （higher about 30% ） ;The expression of MAPK was promoted under the treatment of a low GABA concentration （1mmol/L）. However, the elongation of primary roots was inhibited at a high GABA concentration （10- 100 mmol/L）,demonstrating the typical feature of ethylene response effect. The expression of ACS1 was enhanced by different GABA concentration, 100 mmol/L in leaves and 10 mmol/L in roots. Different expression of MAPK and ACS1 to GABA signals may be involved different signal transduction pathway.