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Systematic deletion of the ER lectin chaperone genes reveals their roles in vegetative growth and male gametophyte development in Arabidopsis
Author(s) -
Vu Kien Van,
Nguyen Ngoc Trinh,
Jeong Chan Young,
Lee YongHwa,
Lee Hojoung,
Hong SukWhan
Publication year - 2017
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.13435
Subject(s) - biology , arabidopsis , calreticulin , calnexin , endoplasmic reticulum , gametophyte , genetics , gene , er retention , chaperone (clinical) , microbiology and biotechnology , mutant , pollen , botany , pathology , medicine
Summary Calnexin ( CNX ) and calreticulin ( CRT ) are homologous lectin chaperones in the endoplasmic reticulum ( ER ) that facilitate glycoprotein folding and retain folding intermediates to prevent their transit via the secretary pathway. The Arabidopsis genome has two CNX ( CNX 1 and CNX 2 ) and three CRT ( CRT 1 , CRT 2 and CRT 3 ) homologs. Despite growing evidence of the biological roles of CNX s and CRT s, little is understood about their function in Arabidopsis growth and development under normal conditions. Here, we report that the deletion of CNX 1 , but not of CNX 2 , in the crt1 crt2 crt3 triple mutation background had an adverse effect on pollen viability and pollen tube growth, leading to a significant reduction in fertility. The cnx1 crt1 crt2 crt3 quadruple mutation also conferred severe defects in growth and development, including a shortened primary root, increased root hair length and density, and reduced plant height. Disruption of all five members of the CNX / CRT family was revealed to be lethal. Finally, the abnormal phenotype of the cnx1 crt1 crt2 crt3 quadruple mutants was completely rescued by either the CNX 1 or CNX 2 cDNA under the control of the CNX 1 promoter, suggesting functional redundancy between CNX 1 and CNX 2. Taken together, these results provide genetic evidence that CNX and CRT play essential and overlapping roles during vegetative growth and male gametophyte development in Arabidopsis.