Yulu Zhou,Ruixia Niu,Zhijuan Tang,Rui Mou,Zhao Wang,Sitao Zhu,Hongchun Yang,Pingtao Ding &Guoyong Xu.Nature Plants（胥国勇)

Abstract：

        Translational reprogramming is a fundamental layer of immune regulation, but how such a global regulatory mechanism operates remains largely unknown. Here we perform a genetic screen and identifyArabidopsisHEM1 as a global translational regulator of plant immunity. The loss ofHEM1causes exaggerated cell death to restrict bacterial growth during effector-triggered immunity (ETI). By improving ribosome footprinting, we reveal that thehem1mutant increases the translation efficiency of pro-death immune genes. We show that HEM1 contains a plant-specific low-complexity domain (LCD) absent from animal homologues. This LCD endows HEM1 with the capability of phase separation in vitro and in vivo. During ETI, HEM1 interacts and condensates with the translation machinery; this activity is promoted by the LCD. CRISPR removal of this LCD causes more ETI cell death. Our results suggest that HEM1 condensation constitutes a brake mechanism of immune activation by controlling the tissue health and disease resistance trade-off during ETI.