AUTHOR=Wang Le , Wang Huiyu , He Shengfu , Meng Fanshan , Zhang Chuanzhong , Fan Sujie , Wu Junjiang , Zhang Shuzhen , Xu Pengfei 

TITLE=GmSnRK1.1, a Sucrose Non-fermenting-1(SNF1)-Related Protein Kinase, Promotes Soybean Resistance to Phytophthora sojae

JOURNAL=Frontiers in Plant Science

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2019.00996

DOI=10.3389/fpls.2019.00996

ISSN=1664-462X

ABSTRACT=<p>Phytophthora root and stem rot, a destructive disease of soybean [<italic>Glycine max</italic> (L.) Merr.], is caused by the oomycete <italic>Phytophthora sojae</italic>. However, how the disease resistance mechanisms of soybean respond to <italic>P. sojae</italic> infection remains unclear. Previously, we showed that GmWRKY31, which interacts with a sucrose non-fermenting-1(SNF1)-related protein kinase (SnRK), enhances resistance to <italic>P. sojae</italic> in soybean. Here, we report that the membrane-localized SnRK GmSnRK1.1 is involved in the soybean host response to <italic>P. sojae</italic>. The overexpression of <italic>GmSnRK1.1</italic> (<italic>GmSnRK1.1</italic>-OE) increased soybean resistance to <italic>P. sojae</italic>, and the RNA interference (RNAi)-mediated silencing of <italic>GmSnRK1.1</italic> (<italic>GmSnRK1.1</italic>-R) reduced resistance to <italic>P. sojae</italic>. Moreover, the activities and transcript levels of the antioxidant enzymes superoxide dismutase and peroxidase were markedly higher in the <italic>GmSnRK1.1</italic>-OE transgenic soybean plants than in the wild type (WT), but were reduced in the <italic>GmSnRK1.1</italic>-R plants. Several isoflavonoid phytoalexins related genes <italic>GmPAL</italic>, <italic>GmIFR</italic>, <italic>Gm4CL</italic> and <italic>GmCHS</italic> were significantly higher in “Suinong 10” and <italic>GmSnRK1.1</italic>-OE lines than these in “Dongnong 50,” and were significantly lower in <italic>GmSnRK1.1</italic>-R lines. In addition, the accumulation of salicylic acid (SA) and the expression level of the SA biosynthesis-related gene were significantly higher in the <italic>GmSnRK1.1</italic>-OE plants than in the WT and <italic>GmSnRK1.1</italic>-R plants, moreover, SA biosynthesis inhibitor treated <italic>GmSnRK1.1</italic>-R lines plants displayed clearly increased pathogen biomass compared with H<sub>2</sub>O-treated plants after 24 h post-inoculation. These results showed that GmSnRK1.1 positively regulates soybean resistance to <italic>P. sojae</italic>, potentially functioning via effects on the expression of SA-related genes and increased accumulation of SA.</p>