AUTHOR=Han Ning , Ji Xing-Long , Du Yuan-Peng , He Xi , Zhao Xin-Jie , Zhai Heng 

TITLE=Identification of a Novel Alternative Splicing Variant of VvPMA1 in Grape Root under Salinity

JOURNAL=Frontiers in Plant Science

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2017.00605

DOI=10.3389/fpls.2017.00605

ISSN=1664-462X

ABSTRACT=<p>It has been well-demonstrated that the control of plasma membrane H<sup>+</sup>-ATPase (PM H<sup>+</sup>-ATPase) activity is important to plant salt tolerance. This study found a significant increase in PM H<sup>+</sup>-ATPase (PMA) activity in grape root exposed to NaCl. Furthermore, 7 <italic>Vitis vinifera</italic> PM H<sup>+</sup>-ATPase genes (<italic>VvPMAs</italic>) were identified within the grape genome and the expression response of these <italic>VvPMAs</italic> in grape root under salinity was analyzed. Two <italic>VvPMAs</italic> (<italic>VvPMA1</italic> and <italic>VvPMA3</italic>) were expressed more strongly in roots than the other five <italic>VvPMAs</italic>. Moreover, roots exhibited diverse patterns of gene expression of <italic>VvPMA1</italic> and <italic>VvPMA3</italic> responses to salt stress. Interestingly, two transcripts of <italic>VvPMA1</italic>, which were created through alternative splicing (AS), were discovered and isolated from salt stressed root. Comparing the two <italic>VvPMA1</italic> cDNA sequences (designated <italic>VvPMA1</italic>α and <italic>VvPMA1</italic>β) with the genomic sequence revealed that the second intron was retained in the <italic>VvPMA1</italic>β cDNA. This intron retention was predicted to generate a novel VvPMA1 through N-terminal truncation because of a 5′- terminal frame shift. Yeast complementation assays of the two splice variants showed that <italic>VvPMA1</italic>β could enhance the ability to complement <italic>Saccharomyces cerevisiae</italic> deficient in PM H<sup>+</sup>-ATPase activity. In addition, the expression profiles of <italic>VvPMA1</italic>α and <italic>VvPMA1</italic>β differed under salinity. Our data suggests that through AS, the N-terminal length of VvPMA1 may be regulated to accurately modulate PM H<sup>+</sup>-ATPase activity of grape root in salt stress.</p>