AUTHOR=Xiong Yang , Fan Xu-Hong , Wang Qiang , Yin Zheng-Gong , Sheng Xue-Wen , Chen Jun , Zhou Yong-Bin , Chen Ming , Ma You-Zhi , Ma Jian , Xu Zhao-Shi 

TITLE=Genomic Analysis of Soybean PP2A-B′′ Family and Its Effects on Drought and Salt Tolerance

JOURNAL=Frontiers in Plant Science

VOLUME=12

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.784038

DOI=10.3389/fpls.2021.784038

ISSN=1664-462X

ABSTRACT=<p>Abiotic stresses induce the accumulation of reactive oxygen species (ROS) and significantly affect plant growth. Protein phosphatase 2A (PP2A) plays an important role in controlling intracellular and extracellular ROS signals. However, the interaction between PP2A, ROS, and stress tolerance remains largely unclear. In this study, we found that the B<inline-formula><mml:math id="INEQ2" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi /><mml:mmultiscripts><mml:msup><mml:mi /><mml:mo>′</mml:mo></mml:msup><mml:mprescripts /><mml:none /><mml:mo>′</mml:mo></mml:mmultiscripts></mml:msup></mml:math></inline-formula> subunit of PP2A (PP2A-B<inline-formula><mml:math id="INEQ3" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi /><mml:mmultiscripts><mml:msup><mml:mi /><mml:mo>′</mml:mo></mml:msup><mml:mprescripts /><mml:none /><mml:mo>′</mml:mo></mml:mmultiscripts></mml:msup></mml:math></inline-formula>) can be significantly induced and was analyzed using drought- and salt-induced soybean transcriptome data. Eighty-three soybean <italic>PP2A-B<inline-formula><mml:math id="INEQ4" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi /><mml:mmultiscripts><mml:msup><mml:mi /><mml:mo>′</mml:mo></mml:msup><mml:mprescripts /><mml:none /><mml:mo>′</mml:mo></mml:mmultiscripts></mml:msup></mml:math></inline-formula></italic> genes were identified from the soybean genome <italic>via</italic> homologous sequence alignment, which was distributed across 20 soybean chromosomes. Among soybean <italic>PP2A-B<inline-formula><mml:math id="INEQ5" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi /><mml:mmultiscripts><mml:msup><mml:mi /><mml:mo>′</mml:mo></mml:msup><mml:mprescripts /><mml:none /><mml:mo>′</mml:mo></mml:mmultiscripts></mml:msup></mml:math></inline-formula></italic> family genes, 26 <italic>GmPP2A-B<inline-formula><mml:math id="INEQ6" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi /><mml:mmultiscripts><mml:msup><mml:mi /><mml:mo>′</mml:mo></mml:msup><mml:mprescripts /><mml:none /><mml:mo>′</mml:mo></mml:mmultiscripts></mml:msup></mml:math></inline-formula></italic> members were found to be responsive to drought and salt stresses in soybean transcriptome data. Quantitative PCR (qPCR) analysis demonstrated that <italic>GmPP2A-B<inline-formula><mml:math id="INEQ7" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi /><mml:mmultiscripts><mml:msup><mml:mi /><mml:mo>′</mml:mo></mml:msup><mml:mprescripts /><mml:none /><mml:mo>′</mml:mo></mml:mmultiscripts></mml:msup></mml:math></inline-formula>71</italic> had the highest expression levels under salt and drought stresses. Functional analysis demonstrated that overexpression of <italic>GmPP2A-B<inline-formula><mml:math id="INEQ8" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi /><mml:mmultiscripts><mml:msup><mml:mi /><mml:mo>′</mml:mo></mml:msup><mml:mprescripts /><mml:none /><mml:mo>′</mml:mo></mml:mmultiscripts></mml:msup></mml:math></inline-formula>71</italic> in soybeans can improve plant tolerance to drought and salt stresses; however, the interference of <italic>GmPP2A-B<inline-formula><mml:math id="INEQ9" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi /><mml:mmultiscripts><mml:msup><mml:mi /><mml:mo>′</mml:mo></mml:msup><mml:mprescripts /><mml:none /><mml:mo>′</mml:mo></mml:mmultiscripts></mml:msup></mml:math></inline-formula>71</italic> in soybean increased the sensibility to drought and salt stresses. Further analysis demonstrated that overexpression of <italic>GmPP2A-B<inline-formula><mml:math id="INEQ10" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi /><mml:mmultiscripts><mml:msup><mml:mi /><mml:mo>′</mml:mo></mml:msup><mml:mprescripts /><mml:none /><mml:mo>′</mml:mo></mml:mmultiscripts></mml:msup></mml:math></inline-formula>71</italic> in soybean could enhance the expression levels of stress-responsive genes, particularly genes associated with ROS elimination. These results indicate that PP2A-B<inline-formula><mml:math id="INEQ11" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi /><mml:mmultiscripts><mml:msup><mml:mi /><mml:mo>′</mml:mo></mml:msup><mml:mprescripts /><mml:none /><mml:mo>′</mml:mo></mml:mmultiscripts></mml:msup></mml:math></inline-formula> can promote plant stress tolerance by regulating the ROS signaling, which will contribute to improving the drought resistance of crops.</p>