Overexpression of a rice <i>eIF2</i>β variant modulates leaf age-dependent resistance to pathogens in <i>Arabidopsis thaliana</i>

Plants display diverse resistance responses that are influenced by their age and the timing of pathogen exposure. In <i>Arabidopsis thaliana</i> (Arabidopsis), nonhost resistance (NHR) to <i>Pyricularia oryzae</i> varies with leaf age and the time of inoculation. While the circadian clock and photoperiod have been linked to the time-dependent regulation of NHR in Arabidopsis, the mechanism underlying leaf age-dependent NHR remains unclear. To identify key players in leaf age-dependent NHR to <i>P. oryzae</i> in Arabidopsis, we utilized rice-Full-length cDNA OvereXpressing (FOX) Arabidopsis lines and identified the rice <i>eIF2</i>β (eukaryotic translation initiation factor 2 beta subunit) variant (Os03g0333300-2). Overexpression of the rice <i>eIF2</i>β variant reduced NHR to <i>P. oryzae</i> and modulated host resistance (HR) to <i>Colletotrichum higginsianum</i> in Arabidopsis. The effect of Os03g0333300-2 expression on resistance is dependent on leaf age in Arabidopsis. These results suggest that overexpression of the rice <i>eIF2</i>β variant Os03g0333300-2 could contribute to defense responses in a leaf age-dependent manner in Arabidopsis. Our findings might suggest the involvement of the rice <i>eIF2</i>β variant in eIF2-dependent translation regulation of resistance response to pathogens in plants.