Epsilon Archive for Student Projects

Abstract

Crop production is essential for human consumption; however, production can suffer due to
pathogens and environmental factors. Plants have natural immune defense mechanisms to fend off
these pathogens. When under attack, plants sense pathogens through pattern recognition receptors
(PRRs), namely receptor-like kinase and receptor-like protein, and then employ Pattern-triggered
immunity (PTI) to initiate plant defense. Plants also secrete endogenous peptides called
phytocytokines to modulate PTI. However, these mechanisms are not always sufficient and crop
loss occurs. Rice is an important crop that suffers from rice blast, a disease caused by rice blast
fungus Magnaporthe oryzae. Receptor-like cytoplasmic kinases (RLCKs) work downstream of
PRRs to relay signals. Despite a large number of RLCKs existing in rice, we have limited
information on their functions. In this study, we used three experiment sets: 1) rice plants treated
with rice blast fungus, 2) rice suspension cells treated with a MAMP chitin, and 3) rice suspension
cells treated with chitin, and two phytocytokines IRP and RALF to clarify OsRLCK expression
patterns during immune responses. By studying these expression patterns, we aim to develop a better
understanding of rice immunity and thereby develop methods to improve rice production. Through
differential transcript expression analyses, we uncovered differentially expressed genes (DEGs)
between treatments and controls. After extracting the DEGs from 379 OsRLCKs, we tried to obtain
expression patterns of OsRLCKs involved in rice immunity. We also located 4 candidates of
AP2/ERF transcription factor genes that may positively regulate OsRLCK expression through
binding to cis-regulatory elements of the OsRLCK genes identified in the study. The GO analysis
revealed gene functions involved in IRP- and RALF-specific regulative pathways. Our findings
provide more information for understanding RLCK regulation in rice immunity and candidate RLCK
genes for future research.