The cold-responsive (COR) genes play an important role in cold acclimation of higher plants. Here, a tight correlation between chloroplast functionality and COR15A expression, and the functional characterization of Arabidopsis COR15A involved in salt/osmotic stress, were revealed. COR15A gene is light inducible and expressed in light-grown seedlings. The expression level of COR15A was reduced when chloroplasts were damaged by norflurazon treatment. By using several albino mutants, seca1, secy1, and tic20, all of which exhibited severe defects in both structure and function of chloroplast, it was shown that the accumulation of COR15A mRNA depends on chloroplast functionality. Real-time RT-PCR and GUS-staining assays demonstrated that COR15A was induced by salt/osmotic stress partially via ABA. Overexpression of COR15A in Arabidopsis resulted in the seedlings displaying hypersensitivity to salt/osmotic stress. All these results suggest that plant acquire the ability to fully express COR15A only after the development of functional chloroplasts, COR15A may be involved in response to salt/ osmotic stress during early stages of plant development.
Hydrogen sulfide (H2S) is an important signaling molecule involved in several stress-resistance processes in plants, such as drought and heavy metal stresses. However, little is known about the roles of H2S in responses to chilling stress. In this paper, we demonstrated that chilling stress enhance the H2S levels, the H2S synthetase (L-/D-cysteine desulfhydrase, L/DCD) activities, and the expression of L/DCD gene in Vitis vinifera L. ‘F-242’. Furthermore, the seedlings were treated with sodium hydrosulfide (NaHS, a H2S donor) and hypotaurine (HT, a H2S scavenger) at 4°C to examine the effects of exogenous H2S on grape. The results revealed that the high activity of superoxide dismutase and enhanced expression of VvICE1 and VvCBF3 genes, but low level of superoxide anion radical, malondialdehyde content and cell membrane permeability were detected after addition of NaHS. In contrast, HT treatment displayed contrary effect under the chilling temperature. Taken together, these data suggested that H2S might be directly involved in the cold signal transduction pathway of grape.
For this study we constructed an integrated evaluation model of water quantity and quality that couples the supply-demand balance system, water consumption balance system, and a simulation model of water quality. In order to realize the dual water supply, the constraint equation of dual water supply has been added in the supply-demand balance system. The water pollution-induced water shortage quantitative identification approach and the evaluation index of the proportion between social economic water consumption and ecological water use has been put forward to evaluate the satisfaction degree of ecological water use and water quality based on simulations of water quantity and quality. This study utilizes an application of the water quantity and quality evaluation model in the main stream of the Huangshui River (Qinghai, China). The evaluation results provide support for future water resource development and management as follows: (1) the water quality-index water shortage rate of the entire area was 3.7% and in some local areas reached 25.7% (2) the proportion of ecological water use of each water resource partition were all more than 80% (3) although the ecological water demand in the rivers could be satisfied, the standard-reaching rate of water quality was very low due to the total pollutants not having been controlled.
Several aspects of in vitro culture have potential for cereal improvement. This paper focuses on evaluation of somaclonal variation (SV) from immature embryo callus culture, and doubled haploid (DH) production via anther culture in barley. Genetically stable SV was observed for several seedling morphological traits such as albino, yellow, light green and lethal. SV occurred at approximately half the frequency of azide-induced mutagenesis. The potential for widespread application of anther culture-mediated DH production in barley breeding and genetic studies was increased through culture procedure improvements and understanding the inheritance of anther culture response. Methodology improvements included substitution of inexpensive gelrite for expensive ficoll or agarose, ability to grow anther donor plants under field as well as growth chamber conditions and flexibility in cold pretreatment/storage of anther donor spikes for 4-6 weeks prior to anther plating. From diallel analysis, inheritance of anther culture response was complex with additive and dominance effects for embryoid formation, total plant regeneration and green plant regeneration and reciprocal effects (maternal) for green plant regeneration. High x low responder crosses generated F₁’s that were intermediate in response and low x low crosses sometimes produced F₁ heterosis for green plant regeneration. Therefore, some recalcitrant types appear to be usable in anther culture DH production systems within a breeding program.
Abscisic acid (ABA) plays critical roles in plant growth and development as well as in plants’ responses to abiotic stresses. We previously isolated VvWRKY13, a novel transcription factor, from Vitis vinifera (grapevine), and here we present evidence that VvWRKY13 may regulate ABA biosynthesis in plants. When VvWRKY13 was ectopically expressed in Arabidopsis, the transgenic lines showed delayed seed germination, smaller stomatal aperture size, and several other phenotypic changes, indicating elevated ABA levels in these plants. Sequence analysis of several genes that are involved in grapevine ABA synthetic pathway identified WRKY-specific binding elements (W-box or W-like box) in the promoter regions. Indeed, transient overexpression of VvWRKY13 in grapevine leaves significantly increased the transcript levels of ABA synthetic pathway genes. Taken together, we conclude that VvWRKY13 may promote ABA production by activating genes in the ABA synthetic pathway.
Bulked segregant analysis combined with specific length amplified fragment sequencing techniques have been applied to determine the fine genetic mapping of fruit flesh thickness-related genes in cucumber. Herein, the Csa2M058670.1 gene was subjected to real time fluorescence quantitative PCR (qRT-PCR) and sequence analysis, indicating a strong correlation with cucumber fruit flesh thickness. Expression and characterisation of the Csa2M058670.1 gene were performed based on previous studies. The results of the fluorescence-based quantitative PCR showed that Csa2M058670.1 was expressed in all organs, but levels were highest in fruit peel, fruit flesh, and female flowers. Furthermore, Csa2M058670.1 expression was induced by abiotic stresses including drought, low temperature, and high salt. Domain analysis revealed that the protein encoded by Csa2M058670.1 possesses an SET (Su(var), Enhancern of zeste CE(z), and Trithorax) domain that may control cell division and differentiation. Therefore, we speculated that Csa2M058670.1 might affect fruit flesh thickness in cucumbers by influencing cell division.
Over the last 5 decades, runoff from the upstream area of the Yongding River basin has greatly decreased because of changes in the climate and in the intensity of human activities. The Mann-Kendall rank correlation trend test, cumulative anomaly method, and double mass curve of precipitation and runoff were applied to analyse the hydrological sequence trends and altered features in the upstream area of the Yongding River during 1960-2010. The influences of climate change and human activities on changes in runoff were quantitatively assessed using a climate elasticity method based on the Budyko hypothesis. In this paper, the results showed that, on average, runoff in the 3 basins in the upstream area of the Yongding showed a significant (99% confidence level) downward trend. We found that human activities were the main driving factors for the decline in annual runoff in the Yanghe River basin, Sanggan River basin, and upstream area of the Yongding River basin, accounting for 82.04%, 81.51%, and 75.69% of the runoff reduction, respectively, during evaluation period I, and accounting for 77.94%, 72.73%, and 73.37% of runoff reduction, respectively, during evaluation period II. However, the impact of climate variability on runoff gradually increased over time in the 3 basins.
The toxicity of arsenic (As) in different polluted areas and its effects on human and animal health is a big concern all over the world. Although a wetland ecosystem is a “green filter,” this specific function would be impaired by high As content in wetland sediments. The distribution of As in wetland sediments and its linkages to environmental factors have not been fully explored. In this study, sediment samples (0-10 cm) and water samples were collected from different locations along the Yangzonghai lakeside, located in the city of Yuxi, Yunnan province of China, and were analyzed for As fractions. Results showed that As content in sediments ranged from 7.550 to 89.83 mg·kg⁻¹ (with a mean value of 16.11 mg·kg⁻¹). The As fractions were dominated by residual fraction (B4) (up to 62.67%), and the mean contents from high to low were: B4 (10.10) > oxidizable fraction (B3) (2.600) > acid extractable fraction (B1) (2.270) > reducible fraction (B2) (2.170). The distribution of As in sediments was mainly influenced by point-source pollution. In addition, the lack of significant correlation between As content and the different landscapes in the buffer zone of Yangzonghai lakeside indicated that the land use around the lakeside wetland (mainly non-point source pollution) may not have a significant impact on As fractions. Among environmental factors, As contents were positively (p<0.05) correlated to dicalcium phosphate (Ca₂-P) and octacalcium phosphate (Ca₈-P). However, phosphorus distribution revealed that phosphorus in sediments was mainly caused by non-point source pollution, and thus farmland fertilizer, domestic waste, and livestock manure should be controlled. As fractions such as B1, B2, and B3 in wetland sediments were positively correlated with dissolved oxygen (DO) and redox potential (Eh), but negatively correlated to organic matter (OM), pH, and lime-type phosphorus (Ca₁₀-P) when the upstream area was dominated by agricultural lands, indicating that these parameters may affect the release of As into sediments.
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