AUTHOR=Chen Qi , Jin Yan , Zhang Zhonghua , Cao Meng , Wei Guanyun , Guo Xiaorui , Zhang Jian , Lu Xueyan , Tang Zhonghua 

TITLE=Ionomic and Metabolomic Analyses Reveal Different Response Mechanisms to Saline–Alkali Stress Between Suaeda salsa Community and Puccinellia tenuiflora Community

JOURNAL=Frontiers in Plant Science

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.774284

DOI=10.3389/fpls.2021.774284

ISSN=1664-462X

ABSTRACT=<p>Soil salinization imposes severe stress to plants, inhibits plant growth, and severely limits agricultural productivity and land utilization. The response of a single plant to saline-alkali stress has been well investigated. However, the plant community that usually works as a group to defend against saline–alkali stress was neglected. To determine the functions of plant community, in our current work, <italic>Suaeda salsa</italic> (<italic>S. salsa</italic>) community and <italic>Puccinellia tenuiflora</italic> (<italic>P. tenuiflora</italic>) community, two communities that are widely distributed in Hulun Buir Grassland in Northeastern China, were selected as research objects. Ionomic and metabolomic were applied to compare the differences between <italic>S. salsa</italic> community and <italic>P. tenuiflora</italic> community from the aspects of ion transport and phenolic compound accumulation, respectively. Ionomic studies demonstrated that many macroelements, including potassium (K) and calcium (Ca), were highly accumulated in <italic>S. salsa</italic> community whereas microelement manganese (Mn) was highly accumulated in <italic>P. tenuiflora</italic> community. In <italic>S. salsa</italic> community, transportation of K to aboveground parts of plants helps to maintain high K<sup>+</sup> and low Na<sup>+</sup> concentrations whereas the accumulation of Ca triggers the salt overly sensitive (SOS)-Na<sup>+</sup> system to efflux Na<sup>+</sup>. In <italic>P. tenuiflora</italic> community, enrichment of Mn in roots elevates the level of Mn-superoxide dismutase (SOD) and increases the resistance to saline–alkali stress. Metabolomic studies revealed the high levels of C6C1-compounds and C6C3C6-compounds in <italic>S. salsa</italic> community and also the high levels of C6C3-compounds in <italic>P. tenuiflora</italic> community. C6C1-compounds function as signaling molecules to defend against stress and may stimulate the accumulation of C6C3C6-compounds. C6C3-compounds contribute to the elimination of free radicals and the maintenance of cell morphology. Collectively, our findings determine the abundance of phenolic compounds and various elements in <italic>S. salsa</italic> community and <italic>P. tenuiflora</italic> community in Hulun Buir Grassland and we explored different responses of <italic>S. salsa</italic> community and <italic>P. tenuiflora</italic> community to cope with saline–alkali stress. Understanding of plant response strategies from the perspective of community teamwork may provide a feasible and novel way to transform salinization land.</p>