Rice plants response to modulation of the ERECTA signaling

ABSTRACT The ERECTA family of receptors (ERfs), encoding leucine-rich repeat receptor-like kinases (LRR-RLKs), can regulate multiple aspects of plant development and abiotic stress responses. The rice (Oryza sativa) genome contains three ERfs, namely ERECTA 1 (OsER1), ERECTA 2 (OsER2), and ERECTA-LIKE (OsERL). However, there is limited information currently available on their expression pattern during the plant developmental stages. The expression pattern of OsERfs genes at reproductive stages from the booting (R2) to milk (R6) stage in Nipponbare cultivar and the transgenic plants expressing a truncated Arabidopsis ERECTA (ER) lacking the kinase domain (∆Kinase) were studied. The ∆Kinase functions as a dominant-negative receptor and presumably disrupts ER signaling in rice. The highest level of rice ERfs (OsERfs) expression was observed at the heading (R3) and flowering (R4) stages. ∆Kinase expression induced the compensation effect and increased the expression of endogenous OsERfs genes, possibly due to the suppression of ER signaling. The response to heat stress was evaluated at the reproductive stages to test the functional effect of the upregulated OsERfs on transgenic plants. Although transgenic plants exhibited enhanced growth during the vegetative stages, they succumbed to heat stress during the grain filling stages. Overall, the ∆Kinase plants generated in this research serve as essential resources to study the role of OsERfs in the response of plants to developmental and environmental stress.