分析了F-box基因FOA1(F-box overexpressed/oppressed ABA signaling)在拟南芥不同组织器官的表达模式,以及ABA和NaCl对其表达的调节.结果发现,FOA1在根和花中表达较高茎中表达较低;外源ABA和NaCl处理能迅速诱导FOA1基因的表达.分析ABA处理条件下,过量表达株系FOA1ox1,FOA1ox2和T-DNA插入突变体foa1的表型发现,突变体foa1的种子萌发率下降、根较短、气孔开度较大、脯氨酸积累增加,且对外源ABA敏感;过量表达株系的表型则相反,对ABA的敏感性降低.ABA处理条件下,一系列ABA信号转导转录因子在foa1突变体中的转录水平比野生型高,而ABA及胁迫应答基因在foa1突变体中的转录水平则比野生型低.这些研究结果表明,FOA1是ABA信号通路相关基因,并可能起负调控作用.
The expression of FOAl （F-box overexpressed/oppressed ABA signaling） in different organs of Arabidopsis, and in response to ABA and NaCI, was analyzed. The expression level of FOAl is higher in the root and is lower in the stem, and is induced rapidly by ABA and NaC1. The phenotypes of T-DNA insertion mutant foal and FOAl overexpression lines FOAloxl and FOAlox2 were analyzed. The foal mutant exhibited a lower germination rate, shorter root length, more stomatal opening, in- creased proline accumulation and hypersensitivity to ABA compared with the wild type. In contrast, the overexpression lines showed lower sensitivity to ABA than the wild type. The expression levels of several ABA and stress-responsive transcription factors and genes were altered in the foal mutant in response to ABA. Compared with the wild type, the expression levels of ABA-responsive transcription factors were higher, but ABA and stress-responsive genes were lower in foal mutant. This study demonstrates that FOAl is an ABA signaling-related gene, and may play a negative role in ABA signaling.
