Bcl-2/E1B-19K-interacting protein 3 (BNIP3) is a member of the apoptotic B-cell lymphoma-2 family that regulates cell death. Although BNIP3 targeted normally to the mitochondrial outer membrane by its transmembrane domain was originally considered to be essential for its pro-apoptotic activity, accumulating evidence has shown that BNIP3 is localized to endoplasmic reticulum at physiological conditions and that forced expression of BNIP3 can initiate cell death via multiple pathways depending on the subcellular compartment it targets. Targeting BNIP3 to endoplasmic reticulum has been shown to participate in cell death during endoplasmic reticulum stress. However, the molecular events responsible for BNIP3-induced cell death in the endoplasmic reticulum remain poorly understood. In the present study, the transmembrane domain of BNIP3 was replaced with a segment of cytochrome b5 that targets BNIP3 into endoplasmic reticulum, which induced cell death as effectively as its wild-type molecule in the SW480 cell line (colon carcinoma). Furthermore, a pan-caspase inhibitor, z-VAD-fmk, and PD150606, a specific calpain inhibitor, both significantly suppressed the endoplasmic reticulum-targeted BNIP3- induced cell death. These results suggest that endoplasmic reticulum-targeted BNIP3 induced a mixed mode of cell death requiring both caspases and calpains.
In order to evaluate effect of weedy rice on the photosynthesis and grain filling of cultivated rice, cultivated rice ‘Nanjing 44‘ was planted in the field under different densities of weedy rice ‘JS-Y1‘ for two years. The results showed that net photosynthetic rate (PN), net assimilation rate, grain filling rate, and the grain yield of cultivated rice all decreased with increasing weedy rice density. Furthermore, yield component analysis revealed that increasing weedy rice density had the most significant effect on the percentage of filled grains and the number of rice panicles. The correlation analyses indicated that the yield of cultivated rice was highly correlated with the net photosynthetic rate and the net assimilation rate. Our results illustrated that high density of weedy rice might cause yield losses in cultivated rice by inhibition of photosynthesis and grain filling., X. M. Xu, G. Li, Y. Su, X. L. Wang., and Obsahuje bibliografii
The objective of this study was to evaluate the significance of blue light (B) in the growth and photosynthetic capacity of cucumber. Gas exchange, chlorophyll (Chl) fluorescence kinetics, chloroplast ultrastructure, and leaf growth were investigated to explore the influence of three different light qualities of light emitting diodes (LEDs) on plant morphogenesis and the development of photosynthetic apparatus in cucumber (Cucumis sativus) leaves from emergence to full expansion under weak light [50 μmol(photon) m-2 s-1]. We found that B could significantly increase the leaf area (LA), shoot elongation, Chl a/b, net photosynthetic rate, and stomatal conductance (g s). In addition, the comparisons of maximal quantum yield of PSII photochemistry and the photosynthetic performance index between B-, W (white light)-, and R (red light)-grown leaves suggested that B was essential for the development of photosynthetic apparatus under weak light. B-grown leaves had the lowest Chl content under weak light, however, they had well-developed chloroplasts with the highest degree of stacked lamellae and the lowest starch accumulation. This could explain to a considerable extent the highest net photosynthetic rate per Chl unit. The results demonstrated that B optimized photosynthetic performance by improving the photosynthetic rate, increasing LA, and prolonging active photosynthesis duration under low irradiance. Therefore B is necessary to ensure healthy development of chloroplasts and highly efficient photosynthetic functions in cucumbers under a weak light environment. More importantly, our study also provided theoretical and technical support for the development of light environmental control technology., X. Y. Wang, X. M. Xu, J. Cui., and Obsahuje bibliografii