AUTHOR=Liu Ling , Wang Qiaochu , Zhang Xianghui , Liu Jinliang , Zhang Yanhua , Pan Hongyu 

TITLE=Ssams2, a Gene Encoding GATA Transcription Factor, Is Required for Appressoria Formation and Chromosome Segregation in Sclerotinia sclerotiorum

JOURNAL=Frontiers in Microbiology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.03031

DOI=10.3389/fmicb.2018.03031

ISSN=1664-302X

ABSTRACT=<p>AMS2, <underline>a</underline><underline>m</underline>ulticopy <underline>s</underline>uppressor for the <italic>cpn1</italic> (SpCENP-A) mutant, functions to specifically regulate histone genes transcription and chromosome segregation. As a cell-cycle-regulated GATA transcription factor in eukaryotic organisms, little research has been done on the role of AMS2 protein in pathogenic fungi. In <italic>Sclerotinia sclerotiorum</italic>, <italic>Ssams2</italic> (SS1G_03252) encodes a protein which has been predicted to contain GATA-box domain. Here, <italic>Ssams2</italic>-silenced strains with significantly reduced <italic>Ssams2</italic> gene expression levels exhibited defect in hyphal growth, hyphal branching patterns, compound appressoria differentiation and the oxalic acid production compared to the wild-type (WT) strain. By common bean leaves infection assays, we identified the role of <italic>Ssams2</italic> in full virulence. Furthermore, the numbers of cell nucleus in the same length of mycelium in <italic>Ssams2</italic>-silenced transformants were significantly less than that in the WT strain. The expression levels of histone genes and cell cycle genes in transformants were down-regulated significantly in the RNAi strains. Taken together, our work suggests that the TF SsAMS2 is required for growth, appressoria formation, virulence, and chromosome segregation in <italic>S. sclerotiorum</italic>.</p>