AtMYB32 is required for normal pollen development in Arabidopsis thaliana
AtMYB32 is required for normal pollen development in Arabidopsis thaliana
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DOI：
10.1111/j.1365-313x.2004.02280.x
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发表时间：
2004-12-01
期刊：
影响因子：
7.2
通讯作者：
Parish, RW
中科院分区：
文献类型：
--
作者：
Preston, J;Wheeler, J;Parish, RW
AtMYB32基因是拟南芥R2R3MYB基因家族的一员，编码转录因子。采用Northern杂交、原位杂交和启动子-GUS融合等方法分析其表达模式。AtMYB32在许多组织中都有表达，但在花药绒毡层、柱头乳突和侧根原基中表达最强。ATMYB32-GUS在伤害后的叶片和茎中被诱导，在根原基中被生长素诱导。对T-DNA插入群体进行了筛选，鉴定出两个插入突变体，均为部分雄性不育，50%以上的花粉粒形状扭曲，缺乏细胞质。AtMYB4与AtMYB32密切相关，并抑制肉桂酸4-羟基酶基因。AtMYB4插入突变体和过表达品系都产生了扭曲的花粉粒。在AtMYB32插入突变体中，二氢黄素4-还原酶基因和抗花青素合成酶基因的转录水平下降，而咖啡酸0-甲基转移酶基因的转录水平上升。AtMYB32和AtMYB4表达水平的变化可能通过改变苯丙烷途径的通量，影响花粉壁的组成，从而影响花粉的发育。
AtMYB32 gene is a member of the R2R3 MYB gene family coding for transcription factors in Arabidopsis thaliana. Its expression pattern was analysed using Northern blotting, in situ hybridization and promoter-GUS fusions. AtMYB32 is expressed in many tissues, but most strongly in the anther tapetum, stigma papillae and lateral root primordia. AtMYB32-GUS was induced in leaves and stems following wounding, and in root primordia by auxin. T-DNA insertion populations were screened and two insertion mutants were identified, both of which were partially male sterile, more than 50% of the pollen grains being distorted in shape and lacking cytoplasm. AtMYB4 is closely related to AtMYB32 and represses the CINNAMATE 4-HYDROXYLASE gene. Distorted pollen grains were produced in both AtMYB4 insertion mutant and overexpression lines. In an AtMYB32 insertion mutant, the transcript levels of the DIHYDROFLAVONOL 4-REDUCTASE and ANTHOCYANIDIN SYNTHASE genes decreased while the level of the CAFFEIC ACID 0-METHYLTRANSFERASE transcript increased. Change in the levels of AtMYB32 and AtMYB4 expression may influence pollen development by changing the flux along the phenylpropanoid pathways, affecting the composition of the pollen wall.