AUTHOR=Zhang Chang , Luo Jia-Jun , Zuo Jing-Bo , Zhang Zheng , Wang Shi-Ting , Zhang Xiao-Jia , Fu Tian-Si , Feng Yu-Long 

TITLE=Transcripts related with ammonium use and effects of gibberellin on expressions of the transcripts responding to ammonium in two invasive and native Xanthium species

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.1035137

DOI=10.3389/fpls.2022.1035137

ISSN=1664-462X

ABSTRACT=<p>Soil nitrogen forms are important for exotic plant invasions. However, little effort has been made to study the molecular mechanisms underlying the utilization of different N forms in co-occurring invasive and native plants. The invasive plant <italic>Xanthium strumarium</italic> prefers nitrate relative to ammonium, and mainly invades nitrate-dominated environments, while it co-occurring native congener <italic>X. sibiricum</italic> prefers ammonium. Here, we addressed the genetic bases for the interspecific difference in ammonium use and the effects of gibberellin (GA). Twenty-six transcripts related with GA biosynthesis and ammonium utilization were induced by ammonium in <italic>X. sibiricum</italic>, while only ten in <italic>X. strumarium</italic> and none for ammonium uptake. <italic>XsiAMT1.1a</italic>, <italic>XsiGLN1.1</italic> and <italic>XsiGLT1b</italic> may be crucial for the strong ability to absorb and assimilate ammonium in <italic>X. sibiricum</italic>. All tested transcripts were significantly up-regulated by GA1 and GA4 in <italic>X. sibiricum</italic>. <italic>XsiGA3OX1a</italic>, which was also induced by ammonium, may be involved in this regulation. Consistently, glutamine synthetase activity increased significantly with increasing ammonium-N/nitrate-N ratio for <italic>X. sibiricum</italic>, while decreased for <italic>X. strumarium</italic>. Our study is the first to determine the molecular mechanisms with which invasive and native plants use ammonium differently, contributing to understanding the invasion mechanisms of <italic>X. strumarium</italic> and its invasion habitat selection.</p>