查看更多>>摘要：Drought is one of the major environmental constraints affecting crop productivity. Plants have to adjust their developmental and physiological processes to cope with drought. We previously identified 18 cassava serine/ arginine-rich (SR) proteins that had a pivotal role in alternative splicing in response to environmental stress. However, functional characterization of SR proteins is rarely explored. Here, we characterized the RSZ subfamily gene MeRSZ21b in cassava. The RSZ21b belongs to the RSZ subfamily, which was widely distributed in major crops and was highly conserved. Quantitative RT-PCR assay showed that the expression of MeRSZ21b was significantly induced by drought. Moreover, overexpression of MeRSZ21b in Arabidopsis was hypersensitive to abscisic acid (ABA) in the phases of seed germination and post-germination seedling growth. Meantime, MeRSZ21b overexpression lines were resistant to sorbitol treatment, and quickly closed the stomata when compared with Col-0 under drought condition. Importantly, overexpression of MeRSZ21b resulted in improved drought tolerance through modulating ABA-dependent signaling. Therefore, our findings refine our knowledge of the SR protein-coding genes and provide novel insights for enhancing plant resistance to environmental stress.
查看更多>>摘要：The biosynthesis of putrescine is mainly driven by arginine decarboxylase (ADC) and ornithine decarboxylase (ODC). Hence, in this study, we generated independent ADC and ODC transgenic silenced tomato lines (SilADC and SilODC, respectively) to test the effect of defective ADC and ODC gene expression on root development under nitrate (NN) or ammonium (NA) conditions. The results showed that SilODC seedlings displayed an increase in ADC expression that led to polyamine accumulation, suggesting a compensatory effect of ADC. However, this effect was not observed in SilADC seedlings. These pathways are involved in different growth processes. The SilADC seedlings showed an increase in fresh weight, shoot length, lateral root number and shoot:root ratio under the NN source and an enhancement in fresh weight, and shoot and root length under NA conditions. However, SilODC seedlings displayed greater weight and shoot length under the NN source, whereas a decrease in lateral root density was found under NA conditions. Moreover, two overexpressed ODC lines were generated to check the relevance of the compensatory effect of the ADC pathway when ODC was silenced. These overexpressed lines showed not only an enhancement of almost all the studied growth parameters under both N sources but also an amelioration of ammonium syndrome under NA conditions. Together, these results reflect the importance of both pathways in plant growth, particularly ODC silencing, which requires compensation by ADC induction.
查看更多>>摘要：Photosynthesis plays an important role in plant growth and development. Increasing photosynthetic rate is a main objective of improving crop productivity. Chlorophyll fluorescence is an effective method for quickly evaluating photosynthesis. In this study, four representative chlorophyll fluorescence parameters, that is, maximum quantum efficiency of photosystem II, quantum efficiency of PSII, photochemical quenching, and non-photochemical quenching, of 219 diverse soybean accessions were measured across three environments. The underlying genetic architecture was analyzed by genome-wide association study. Forty-eight SNPs were detected to associate with the four traits and explained 10.43-20.41% of the phenotypic variation. Nine candidate genes in the stable QTLs were predicted. Great differences in the expression levels of the candidate genes existed between the high photosynthetic efficiency accessions and low photosynthetic efficiency accessions. In all, we uncover 17 QTLs associated with photosynthesis-related traits and nine genes that may participate in the regulation of photosynthesis, which can provide references for revealing the genetic mechanism of photosynthesis. These QTLs and candidate genes will provide new targets for crop yield improvement through increasing photosynthesis.
NSTL
Elsevier