Bayer Martin, Nawy Tal, Giglione Carmela, Galli Mary, Meinnel Thierry, Lukowitz Wolfgang
Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
Science. 2009 Mar 13;323(5920):1485-8. doi: 10.1126/science.1167784.
The YODA (YDA) mitogen-activated protein kinase pathway promotes elongation of the Arabidopsis zygote and development of its basal daughter cell into the extra-embryonic suspensor. Here, we show that the interleukin-1 receptor-associated kinase (IRAK)/Pelle-like kinase gene SHORT SUSPENSOR (SSP) regulates this pathway through a previously unknown parent-of-origin effect. SSP transcripts are produced in mature pollen but do not appear to be translated. Instead, they are delivered via the sperm cells to the zygote and the endosperm, where SSP protein transiently accumulates. Ectopic expression of SSP protein in the leaf epidermis is sufficient to activate YDA-dependent signaling. We propose that SSP protein produced from paternal transcripts upon fertilization triggers zygotic YDA activity, providing an essential temporal cue for the regulation of the asymmetric first division.
YODA（YDA）丝裂原活化蛋白激酶途径促进拟南芥合子的伸长及其基部子细胞发育成胚外胚柄。在此，我们表明白细胞介素-1受体相关激酶（IRAK）/类Pelle激酶基因SHORT SUSPENSOR（SSP）通过一种先前未知的亲本来源效应调节该途径。SSP转录本在成熟花粉中产生，但似乎不被翻译。相反，它们通过精细胞传递到合子和胚乳中，SSP蛋白在那里短暂积累。SSP蛋白在叶表皮中的异位表达足以激活依赖YDA的信号传导。我们提出，受精后由父本转录本产生的SSP蛋白触发合子YDA活性，为不对称第一次分裂的调控提供了一个重要的时间线索。
