AUTHOR=Wu Weiwei , Lin Yan , Chen Qianqian , Peng Wenting , Peng Junchu , Tian Jiang , Liang Cuiyue , Liao Hong 

TITLE=Functional Conservation and Divergence of Soybean GmSTOP1 Members in Proton and Aluminum Tolerance

JOURNAL=Frontiers in Plant Science

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2018.00570

DOI=10.3389/fpls.2018.00570

ISSN=1664-462X

ABSTRACT=<p>Proton (H<sup>+</sup>) and aluminum (Al) rhizotoxicity are two major factors limiting crop production in acid soils. Orthologs of the zinc-finger transcription factor, Sensitive To Proton Rhizotoxicity1 (STOP1), have been found to play an essential role in the tolerance to both stresses by regulating the transcription of multiple H<sup>+</sup> and Al tolerant genes. In the present study, color three <italic>GmSTOP1</italic> homologs were identified in the soybean genome. All three <italic>GmSTOP1</italic> exhibited similar properties as reflected by the harboring of four potential zinc finger domains, localizing in the nucleus, and having transactivation activity. Expression profiling showed that H<sup>+</sup> stress slightly modulated transcription of all three <italic>GmSTOP1</italic>s, while Al significantly up-regulated <italic>GmSTOP1-1</italic> and <italic>GmSTOP1-3</italic> in root apexes and <italic>GmSTOP1-3</italic> in basal root regions. Furthermore, complementation assays in an Arabidopsis <italic>Atstop1</italic> mutant line overexpressing these <italic>GmSTOP1</italic>s demonstrated that all three GmSTOP1s largely reverse the H<sup>+</sup> sensitivity of the <italic>Atstop1</italic> mutant and restore the expression of genes involved in H<sup>+</sup> tolerance. In contrast, only GmSTOP1-1 and GmSTOP1-3 could partially recover Al tolerance in the <italic>Atstop1</italic> mutant. These results suggest that the function of three GmSTOP1s is evolutionarily conserved in H<sup>+</sup> tolerance, but not in Al tolerance.</p>