No abstract

An albinic rice is caused by mutation of threonyl-tRNA synthetase, which is essential for plant development by stabilizing of NEP and PEP gene expressions and chloroplast protein synthesis. Chloroplast biogenesis and development depend on complex genetic mechanisms. Apart from their function in translation, aminoacyl-tRNA synthetases (aaRSs) play additional role in gene expression regulation, RNA splicing, and cytokine activity. However, their detailed functions in plant development are still poorly understood. We isolated a lethal albinic seedling (las) mutant in rice. Physiological and ultrastructural analysis of las mutant plants revealed weak chlorophyll fluorescence, negligible chlorophyll accumulation, and defective thylakoid membrane development. By map based cloning we determined that the LAS allele gene encodes threonyl-tRNA synthetase (ThrRS). LAS was constitutively expressed with relatively high level in leaves. NEP-dependent gene transcripts accumulated in the developing chloroplasts, while PEP-dependent transcripts were reduced in the las mutant. This result indicated that PEP activity was impaired. Chloroplast-encoded protein levels were sharply reduced in the las mutant. Biogenesis of chloroplast rRNAs (16S and 23S rRNA) was arrested, leading to impaired translation and protein synthesis. Together, our findings indicated that LAS is essential not only for chloroplast development by stabilizing the NEP and PEP gene expression, but also for protein synthesis and construction of the ribosome system in rice chloroplasts.

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The incidence of tuberculosis is increasing worldwide, especially in developing countries. The prevalence of abdominal tuberculosis has been found to be as high as 12% in people with extrapulmonary tuberculosis. Peritoneal thickening and intestinal adhesions can occur in patients with abdominal tuberculosis. Inguinal hernias are extremely rare in people with abdominal tuberculosis; only 11 cases have been reported in the English-language literature, half of which involved pediatric patients. No definitive guideline on the management of such cases is available. In this report, we describe the unusual finding of an incarcerated inguinal hernia in an adult with abdominal tuberculosis and propose a therapy to treat this complicated disease based on our successful experience.