SummaryThe tissue-specific expression of transgenes is essential in plant breeding programmes to avoid the fitness costs caused by constitutive expression of a target gene. However, knowledge on the molecular mechanisms of tissue-specific gene expression and practicable tissue-specific promoters is limited. In this study, we identified the cis -acting elements of a tissue-specific promoter from rice, P D54O , and tested the application of original and modified P D54O and its cis -elements in the regulation of gene expression. P D54O is a green tissue-specific promoter. Five novel tissue-specific cis -elements (LPSE1, LPSE2, LPSRE1, LPSRE2, PSE1) were characterized from P D54O . LPSE1 activated gene expression in leaf and young panicle. LPSRE2 suppressed gene expression in leaf, root, young panicle and stem, and PSE1 suppressed gene expression in young panicle and stem. LPSRE1 and LPSE2 had dual roles in the regulation of tissue-specific gene expression; both functioned as activators in leaf, but LPSRE1 acted as a repressor in stem and LPSE2 as a repressor in young panicle and root.Transgenic rice plants carrying cry1Ac encoding Bacillus thuringiensis endotoxin, regulated by P D54O , were resistant to leaf-folders, with no Cry1Ac protein found in endosperm or embryo. A reporter gene regulated by a series of truncated P D54O showed various tissue-specific expression patterns. Different fragments of P D54O fused with the constitutive cauliflower mosaic virus 35S promoter suppressed 35S -regulated gene expression in various tissues. P D54O , truncated P D54O and the tissue-specific cis -elements provide useful tools for the regulation of tissue-specific gene expression in rice breeding programmes.

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Heat stress in poultry is deleterious to productive performance. Chlorogenic acid (CGA) exerts antibacterial, anti-inflammatory, and antioxidant properties. This study was conducted to evaluate the effects of dietary supplemental CGA on the intestinal health and cecal microbiota composition of young hens challenged with acute heat stress. 100-day-old Hy-line brown pullets were randomly divided into four groups.The control group (C) and heat stress group (HS) received a basal diet. HS + CGA 300 group and HS + CGA 600 group received a basal diet supplemented with 300-and 600-mg/kg CGA, respectively, for 2 weeks before heat stress exposure. Pullets of HS, HS + CGA 300 , and HS + CGA 600 group were exposed to 38 C for 4 h while the control group was maintained at 25 C. In this study, dietary CGA supplementation had effect on mitigate the decreased T-AOC and T-SOD activities and the increasing of IL-1β and TNFα induced by acute heat stress. Dietary supplementation with 600 mg/kg CGA had better effect on increasing the relative abundance of beneficial bacterial genera, such as Rikenellaceae RC9_gut_group, Ruminococcaceae UCG-005, and Christensenellaceae R-7_group, and deceasing bacteria genera involved in inflammation, such as Sutterella species. Therefore, CGA can ameliorate acute heat stress damage through suppressing inflammation and improved antioxidant capacity and cecal microbiota composition.