Functional studies of rice blast resistance related gene<italic> OsSAMS1</italic>

Abstract

<p id="C3">Rice blast is one of the most devastating diseases in rice, which causes great economic losses to agricultural production. It has been reported that <italic>S-Adenosyl-l-Mmethionine Synthetase</italic> 1 (<italic>OsSAMS1</italic>) is involved in the process of senescence in rice. Transcriptome sequencing analysis showed that the relative expression level of<italic> OsSAMS1</italic> was significantly increased after inoculation with <italic>Magnaporthe oryzae </italic>(<italic>M. oryzae</italic>). However, it remains unclear whether <italic>OsSAMS1</italic> is involved in rice immunity. To verify this, we constructed the knock-out mutants of <italic>OsSAMS1</italic> in the wild type variety ZH11. The results showed that <italic>OsSAMS1</italic> was mainly expressed in rice leaves, and its expression was significantly induced by <italic>M. oryzae</italic> inoculation. Subcellular localization revealed that OsSAMS1 was distributed in the plasma membrane, cytoplasm, and nucleus. Compared to the wild type, the two knockout mutants, <italic>ossams1-1</italic> and <italic>ossams1-2</italic>, displayed enhanced susceptibility upon <italic>M. oryzae</italic> infection, and the expression of pathogenesis-related (<italic>PR</italic>) genes was significantly inhibited. In addition, ethylene synthesis-related genes were also dramatically decreased in both two mutants. These results suggested that <italic>OsSAMS1</italic> was involved in rice immune response and positively regulated rice blast resistance, which lays a foundation for further revealing the molecular mechanism of <italic>OsSAMS1</italic> in plant immunity and provides genetic resources for rice breeding of blast resistance.