How the plasma membrane senses external heat-stress signals to communicate with chloroplasts to orchestrate thermotolerance remains elusive. We identified a quantitative trait locus, Thermo-tolerance 3 ( TT3 ), consisting of two genes, TT3.1 and TT3.2 , that interact together to enhance rice thermotolerance and reduce grain-yield losses caused by heat stress. Upon heat stress, plasma membrane–localized E3 ligase TT3.1 translocates to the endosomes, on which TT3.1 ubiquitinates chloroplast precursor protein TT3.2 for vacuolar degradation, implying that TT3.1 might serve as a potential thermosensor. Lesser accumulated, mature TT3.2 proteins in chloroplasts are essential for protecting thylakoids from heat stress. Our findings not only reveal a TT3.1-TT3.2 genetic module at one locus that transduces heat signals from plasma membrane to chloroplasts but also provide the strategy for breeding highly thermotolerant crops.

Background Diagnostic criteria for sarcopenia have not been established in Chinese. This study established criteria based on the L3-skeletal muscle index (L3-SMI) and assessed its value for outcomes predicting in cirrhotic Chinese patients. Methods Totally 911 subjects who underwent a CT scan at two centres were enrolled in Cohort 1 (394 male and 417 female subjects, aged 20-80 years). The data of those subjects younger than 60 years (365 male and 296 female subjects) were used to determine the reference intervals of the L3-SMI and its influencing factors. Cohort 2 consisted of 480 patients (286 male and 184 female patients) from three centres, and their data were used to investigate the prevalence of sarcopenia and evaluate the value of L3-SMI for predicting the prognosis and complications of cirrhosis. Results Age and sex had the greatest effects on the L3-SMI (P < 0.001). The L3-SMI scores were clearly higher in male patients than in female patients (52.94 ± 8.41 vs. 38.91 ± 5.65 cm 2 /m 2 , P < 0.001) and sharply declined in subjects aged ≥ 60 years. Based on the mean À1.28 × SD among adults aged < 60 years, the L3-SMI cut-off value for sarcopenia was 44.77 cm 2 /m 2 in male patients and 32.50 cm 2 /m 2 in female patients. Using these values, 22.5% of the cirrhotic patients (28.7% of male patients and 11.9% of female patients) were diagnosed with sarcopenia. Compared with non-sarcopenia individuals, sarcopenia patients had lower body mass index (21.28 ± 3.01 vs. 24.09 ± 3.39 kg/m 2 ,

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