The phytohormone abscisic acid (ABA) is involved in the adaptive stress response and regulates expression of many stress-responsive genes, including some transcriptional factors. A bZIP transcription factor, OsABI5, was isolated from the panicle of Oryza sativa L. Expression of the OsABI5 gene was induced by abscisic acid (ABA) and high salinity, and down-regulated by drought and cold (4 degrees C) in seedlings. The OsABI5 protein was localized in the nucleus and has trans-activation activity. The N-terminal of the protein is necessary for its activity. OsABI5 could bind to a G-box element and trans-activate reporter gene expression. Complementation analysis revealed that the expression of OsABI5 driven by the 35S promoter could rescue ABA-insensitivity of abi5-1 during seed germination and result in hypersensitivity to ABA. Over-expression of OsABI5 in rice conferred high sensitivity to salt stress. Repression of OsABI5 promoted stress tolerance and resulted in low fertility of rice. These results suggested that OsABI5 could regulate the adaptive stress response and plant fertility of rice as a transcription factor.

MicroRNAs (miRNAs) are a class of small noncoding RNAs that regulate gene expression by targeting mRNAs to trigger either translation repression or mRNA degradation. miR-125b is down-regulated in human breast cancer cells compared with the normal ones except highly metastatic tumor cells MDA-MB-231. However, few functional studies were designed to investigate metastatic potential of miR-125b. In this study, the effects of miR-125b on metastasis in human breast cancer cells were studied, and the targets of miR-125b were also explored. Transwell migration assay, cell wound healing assay, adhesion assay and nude mice model of metastasis were utilized to investigate the effects of miR-125b on metastasis potential in vitro and in vivo. In addition, it was implied STARD13 (DLC2) was a direct target of miR-125b by Target-Scan analysis, luciferase reporter assay and western blot. Furthermore, activation of STARD13 was identified responsible for metastasis induced by miR-125b through a siRNA targeting STARD13. qRT-PCR, immunofluorescent assay and western blot was used to observe the variation of Vimentin and α-SMA in breast cancer cells. In summary, our study provided new insights into the function of miR-125b during the metastasis of breat cancer cells and also suggested the role of miR-125b in pro-metastasis by targeting STARD13.

Light is the ultimate source of energy for photosynthesis; however, excessive light leads to photooxidative damage and hence reduced photosynthetic efficiency, especially when combined with other abiotic stresses. Although the photosystem II (PSII) reaction center D1 protein is the primary target of photooxidative damage, other PSII core proteins are also damaged and degraded. However, it is still largely unknown whether degradation of D1 and other PSII proteins involves previously uncharacterized proteases. Here, we show that Deg7 is peripherally associated with the stromal side of the thylakoid membranes and that Deg7 interacts directly with PSII. Our results show that Deg7 is involved in the primary cleavage of photodamaged D1, D2, CP47, and CP43 and that this activity is essential for its function in PSII repair. The double mutants deg5 deg7 and deg8 deg7 showed no obvious phenotypic differences under normal growth conditions, but additive effects were observed under high light. These results suggest that Deg proteases on both the stromal and luminal sides of the thylakoid membranes are important for the efficient PSII repair in Arabidopsis (Arabidopsis thaliana).