Open AccessHAPLESS13-Mediated Trafficking of STRUBBELIG Is Critical for Ovule Development in Arabidopsis
Author(s) -
Jia-Gang Wang,
Cheng Feng,
Haihong Liu,
Fu-Rong Ge,
Sha Li,
Hongju Li
Publication year - 2016
Publication title -
plos genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.587
H-Index - 233
eISSN - 1553-7404
pISSN - 1553-7390
DOI - 10.1371/journal.pgen.1006269
Subject(s) - biology , ovule , microbiology and biotechnology , arabidopsis , pollen tube , protein targeting , cell polarity , mutant , botany , genetics , membrane protein , gene , cell , embryo , pollen , membrane , pollination
Planar morphogenesis, a distinct feature of multicellular organisms, is crucial for the development of ovule, progenitor of seeds. Both receptor-like kinases (RLKs) such as STRUBBELIG (SUB) and auxin gradient mediated by PIN-FORMED1 (PIN1) play instructive roles in this process. Fine-tuned intercellular communications between different cell layers during ovule development demands dynamic membrane distribution of these cell-surface proteins, presumably through vesicle-mediated sorting. However, the way it’s achieved and the trafficking routes involved are obscure. We report that HAPLESS13 (HAP13)-mediated trafficking of SUB is critical for ovule development. HAP13 encodes the μ subunit of adaptor protein 1 (AP1) that mediates protein sorting at the trans -Golgi network/early endosome (TGN/EE). The HAP13 mutant, hap13-1 , is defective in outer integument growth, resulting in exposed nucellus accompanied with impaired pollen tube guidance and reception. SUB is mis-targeted in hap13-1 . However, unlike that of PIN2, the distribution of PIN1 is independent of HAP13 . Genetic interference of exocytic trafficking at the TGN/EE by specifically downregulating HAP13 phenocopied the defects of hap13-1 in SUB targeting and ovule development, supporting a key role of sporophytically expressed SUB in instructing female gametogenesis.