Arabidopsis BIG1 and BIG5 are crucial for male gametophyte transmission
Arabidopsis BIG1 and BIG5 are crucial for male gametophyte transmission
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拟南芥 BIG1 和 BIG5 对于雄性配子体传播至关重要
DOI：
10.1111/jipb.12731
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发表时间：
2019-09-01
影响因子：
11.4
通讯作者：
Huang, Jirong
中科院分区：
文献类型：
--
作者：
Suo, Yiping;Huang, Jirong
拟南芥含有五个布雷菲德菌素A抑制的鸟嘌呤核苷酸交换因子（BIGs），它们在囊泡生物合成中起关键作用，用于蛋白质从高尔基体运输到质膜。由BIG 1-BIG 4调节的生物过程被假定为与由BIG 5调节的生物过程不同。然而，我们发现，自花授粉的BIG 1（+/-）big 5角果不产生纯合种子，一些花粉管从BIG 1（+/-）big 5花药在体外生长缓慢，并未能在体内靶向附近的胚珠。我们从BIG 1（+/-）big 5植物的后代中鉴定了big 1 big 5纯合子，BIG 5的表达由花粉特异性启动子pLat 52驱动，表明在双突变体中雄配子体传递被阻断。共聚焦显微镜观察发现BIG 1和BIG 5共定位于高尔基体网络中。因此，我们的数据表明，BIG 1和BIG 5是至关重要的雄配子体传输。
Arabidopsis contains five Brefeldin A-inhibited guanine nucleotide exchange factors (BIGs), which play a critical role in vesicle biogenesis for protein traffic from the Golgi to the plasma membrane. Biological processes regulated by BIG1-BIG4 are postulated to be distinct from those by BIG5. However, we show that the self-pollinated BIG1(+/-) big5 silique do not produce homozygous seeds, and some pollen tubes from BIG1(+/-) big5 anthers grew slowly in vitro and failed to target nearby ovules in vivo. We identified the big1 big5 homozygote from the progeny of BIG1(+/-) big5 plants transformed with BIG5, whose expression is driven by a pollen-specific promoter pLat52, indicating that male gametophyte transmission is blocked in the double mutant. Confocal microscopy indicated that BIG1 and BIG5 are co-localized in trans Golgi network. Thus, our data indicate that BIG1 and BIG5 are crucial for male gametophyte transmission.