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Two ANGUSTIFOLIA genes regulate gametophore and sporophyte development in Physcomitrella patens
Author(s) -
Hashida Yoshikazu,
Takechi Katsuaki,
Abiru Tomomi,
Yabe Noriyuki,
Nagase Hiroaki,
Hattori Koro,
Takio Susumu,
Sato Yoshikatsu,
Hasebe Mitsuyasu,
Tsukaya Hirokazu,
Takano Hiroyoshi
Publication year - 2020
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.14592
Subject(s) - physcomitrella patens , protonema , biology , tip growth , bryopsida , sporophyte , arabidopsis thaliana , ploidy , gene , gametophyte , microbiology and biotechnology , microtubule , botany , mutant , genetics , moss , pollen , pollination , pollen tube
Summary In Arabidopsis thaliana the ANGUSTIFOLIA ( AN ) gene regulates the width of leaves by controlling the diffuse growth of leaf cells in the medio‐lateral direction. In the genome of the moss Physcomitrella patens , we found two normal AN s ( PpAN1‐1 and 1‐2 ). Both PpAN1 genes complemented the A. thaliana an‐1 mutant phenotypes. An analysis of spatiotemporal promoter activity of each PpAN1 gene, using transgenic lines that contained each PpAN1 ‐promoter– uidA (GUS) gene, showed that both promoters are mainly active in the stems of haploid gametophores and in the middle to basal region of the young sporophyte that develops into the seta and foot. Analyses of the knockout lines for PpAN1‐1 and PpAN1‐2 genes suggested that these genes have partially redundant functions and regulate gametophore height by controlling diffuse cell growth in gametophore stems. In addition, the seta and foot were shorter and thicker in diploid sporophytes, suggesting that cell elongation was reduced in the longitudinal direction, whereas no defects were detected in tip‐growing protonemata. These results indicate that both PpAN1 genes in P. patens function in diffuse growth of the haploid and diploid generations but not in tip growth. To visualize microtubule distribution in gametophore cells of P. patens , transformed lines expressing P. patens α‐tubulin fused to sGFP were generated. Contrary to expectations, the orientation of microtubules in the tips of gametophores in the PpAN1‐1/1‐2 double‐knockout lines was unchanged. The relationships among diffuse cell growth, cortical microtubules and AN proteins are discussed.