查看更多>>摘要：This study aimed to investigate the effects of light quality on the morphological traits, photosynthetic pigment content, protective enzyme (superoxide dismutase, peroxidase, and catalase) activity, and bioactive compound (BSP, total phenol, and militarine) content in Bletilla striata. Plants of B. striata were grown under light filtered through three differently colored films. The treatments were red film (RF), yellow film (YF), and blue film (BF), and an uncovered treatment was included as a control (CK). Compared with the B. striata plants in the RF, YF, and CK treatment groups, those receiving BF treatment showed significantly promoted growth of the aerial parts. Meanwhile, the total phenol and militarine contents in B. striata tubers were increased without affecting the accumulation of B. striata polysaccharides. These results show that growing B. striata plants under blue film could be a useful technique to improve quality and production. This technique is conducive to achieving large-scale sustainable production of high-quality plant materials.
查看更多>>摘要：Genes play regulatory roles in plants' response to low-temperature stress. Our understanding of the mechanism of plants' response to low-temperature stress can be expanded by studying the functions of these genes. SfGPX was cloned from Spiraea fritschiana (S. fritschiana) with the highest low-temperature tolerance, to explore the molecular mechanisms of SfGPX in response to low-temperature stress and the physiological mechanisms involved in the regulation of SfGPX to adapt to low temperature, in two species of Spiraea. SfGPX, which was localized in the cytoplasm, was induced by low temperature. The low-temperature tolerance of Spiraea fritschiana was decreased via the interference of SfGPX, and the low-temperature tolerance of Spiraea japonica 'Gold Mound' (S. japonica 'Gold Mound') was elevated via the overexpression of SfGPX. Under low-temperature stress, the photosynthetic capacity of two species of Spiraea was affected by SfGPX; it was higher in the cold-tolerant plants and lower in the cold-intolerant plants. Under low-temperature stress, the transfer intensity of Ca2+ was affected by SfGPX. The transfer intensity of cold-tolerant plants with lower influx level of Ca2+ kinetics was weaker than that of cold-intolerant plants. Under low-temperature stress, the transfer velocity of Ca2+ was affected by SfGPX, and there were slower effluxes of Ca2+ from Ca2+ reservoir in cold-tolerant plants than in cold-intolerant plants. The above results indicate that the response of Spiraea to low temperature is regulated by SfGPX through affecting photosynthetic capacity as well as intensity and velocity of Ca2+ transfer in response to low temperature in Spiraea.
查看更多>>摘要：Seeds often exhibit great plasticity of germination in response to environmental variability and uncertainty. The causes of this plasticity, however, remain poorly understood, and comparative phylogenic analyses of such plasticity are rare. Here, we analyzed a field germination dataset including 474 species exposed to three different levels of light availability, using comparative phylogenetic methods. We calculated the plasticity of germination in response to light availability (PGGP) based on the maximum germination proportion (GP(max)), PGT50 based on the time required to reach 50% of GP(max), PG(RGV) based on the relative germination velocity (RGV), and PG(Total )based on all three of these germination traits. We found that closely related species shared similar light plasticity of germination behavior. Different aspects of germination plasticity in response to light availability were related to specific traits or local environment. PGGP was associated with adult longevity and local water habitat, while PGT50 was related to seed mass and local water habitat, and PG(RGV) was marginally significantly related to plant height. PG(Total) was significantly associated with adult longevity and water habitat. These results suggested that different aspects of germination plasticity were located at specific niche dimension, and local habitats with sufficient soil moisture induced great plasticity germination in response to light environment. As such, they can simplify our understanding of germination, promote the exploration of the general law of germination, and further increase our understanding of species diversity maintenance, adaptation, and evolution from the perspective of germination.
查看更多>>摘要：MADS-domain transcription factors have been identified as key regulators involved in proper flower and fruit development in angiosperms. As members of the MADS-box subfamily, B-sister (B-s) genes have been observed to play an important role during the evolution of the reproductive organs in seed plants. However, their effects on reproductive development in fruit crops, such as tomato (Solanum lycopersicum), remain unclear. Here, we found that SlMBP22 overexpression (SlMBP22-OE) resulted in considerable alterations in floral morphology and affected the expression levels of several floral homeotic genes. Further analysis by yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays demonstrated that SlMBP22 forms dimers with class A protein MACROCALYX (MC) and SEPALLATA (SEP) floral homeotic proteins TM5 and TM29, respectively. In addition, pollen viability and cross-fertilization assays suggested that the defect in female reproductive development was responsible for the infertility phenotype observed in the strong overexpression transgenic plants. Transgenic fruits with mild overexpression exhibited reduced size as a result of reduced cell expansion, rather than impaired cell division. Additionally, SlMBP22 overexpression in tomato not only affected proanthocyanidin (PA) accumulation but also altered seed dormancy. Taken together, these findings may provide new insights into the knowledge of Bs MADS-box genes in flower and fruit development in tomato.
查看更多>>摘要：The high-affinity nitrate transporter 2 (NRT2) proteins play vital roles in both nitrate (NO3-) uptake and translocation in plants. Although the gene families coding the NRT2 proteins have been identified and functionally characterized in many plant species, the systematic identification of NRT2 gene family members has not previously been reported in tomato (Solanum lycopersicum). Moreover, little is known about their expression profiles in response to different environmental stresses. The present study sought to identify the NRT2 gene family members within the tomato genome, and then to characterize them in detail by means of bioinformatics, physiological and expression analyses. Four novel NRT2 genes were identified in the tomato genome, all of which contained the same domain belonging to the major facilitator superfamily (PF07690). The co-expression network of the SlNRT2 genes revealed that they were co-expressed with several other genes in a number of different molecular pathways, including the transport, photosynthesis, fatty acid metabolism and amino acid catabolism pathways. Several phosphorylation sites were predicted in the NRT2 proteins. The SlNRT2 genes interact with many other genes that perform various functions in many crucial pathways within the tomato genome. The sequence variations observed at the gene and protein levels indicate the dynamic regulation of the SlNRT2 gene family members in relation to cell metabolism, particularly with regard to the nitrogen assimilation pathway. The responses of the SlNRT2 genes to drought and salinity stresses are diverse, and they are neither stress-nor tissue-specific. The findings of this study should provide a useful scientific basis for future studies concerning the roles of the NRT2 gene family in plants.
NSTL
Elsevier