The fasciclin-like arabinogalactan protein gene, FLA3, is involved in microspore development of Arabidopsis
The fasciclin-like arabinogalactan protein gene, FLA3, is involved in microspore development of Arabidopsis
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类成束蛋白阿拉伯半乳聚糖蛋白基因 FLA3 参与拟南芥小孢子发育
DOI：
10.1111/j.1365-313x.2010.04344.x
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发表时间：
2010-11-01
期刊：
影响因子：
7.2
通讯作者：
Zhao, Jie
中科院分区：
文献类型：
--
作者：
Li, Jun;Yu, Miao;Zhao, Jie
阿拉伯半乳聚糖蛋白广泛分布于植物组织和细胞中，可能在高等植物的生长发育中发挥作用。据我们所知，目前没有直接证据表明类成束蛋白阿拉伯半乳聚糖蛋白（FLA）参与拟南芥有性生殖。在这项研究中，发现拟南芥FLA3在花粉粒和管中特异性表达。亚细胞定位表明FLA3紧密锚定在质膜上，其糖基磷脂酰肌醇锚定可能影响其定位。 FLA3-RNA干扰转基因植物大约有50%的花粉粒异常（包括收缩和皱纹表型），缺乏活力。细胞学观察表明，花粉败育发生在单核小孢子向双细胞花粉转变过程中，钙荧光白染色可见纤维素分布异常。透射电镜显示，异常花粉的外壁层基本结构正常，但内壁层出现一些异常。总而言之，这些结果表明 FLA3 参与小孢子发育，并可能通过参与纤维素沉积来影响花粉内壁的形成。在FLA3过表达的转基因植物中，雄蕊丝伸长缺陷和雌性生育力降低导致长角果短、结实率低，这表明组织中FLA3的异位表达可能会减少或破坏细胞生长，然后导致整个植物的缺陷。
Arabinogalactan proteins are widely distributed in plant tissues and cells, and may function in the growth and development of higher plants. To our knowledge, there is currently no direct evidence concerning the involvement of fasciclin-like arabinogalactan proteins (FLA) in sexual reproduction in Arabidopsis. In this study, Arabidopsis FLA3 was found to be specifically expressed in pollen grains and tubes. Subcellular localization showed that FLA3 anchors tightly to the plasma membrane, and its glycosylphosphatidylinositol anchor may affect its localization. FLA3-RNA interference transgenic plants had approximately 50% abnormal pollen grains (including shrunken and wrinkled phenotypes) which lacked viability. Cytological observations revealed that pollen abortion occurred during the transition from uninucleate microspores to bicellular pollens, with abnormal cellulose distribution seen by calcofluor white staining. Transmission electron microscopy showed that the basic structure of the exine layer in aberrant pollen was normal, but the intine layer appeared to have some abnormalities. Taken together, these results suggest that FLA3 is involved in microspore development and may affect pollen intine formation, possibly by participating in cellulose deposition. In FLA3-overexpressing transgenic plants, defective elongation of the stamen filament and reduced female fertility led to short siliques with low seed set, which suggested that ectopic expression of FLA3 in tissues may reduce or disrupt cell growth and then result in defects throughout the plant.