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11.
芮孝芳 《水利水电科技进展》2003,23(2):46-50
回顾了水文学在其 30 0余年的形成和发展中曾出现过的若干引人入胜、富有启发性、对学科发展起着重要推动作用的研究成果 .论述了“假设”、“猜想”、“推理”、“比拟”、“综合”和“实验”等研究方法的运用在水文学理论创新中的重要作用 . 相似文献
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庄河市是辽南地区的重要水源地,分析其干旱演变特性有利于该地区水资源的合理开发与利用,对于防旱减灾、合理布局产业结构具有重要的现实意义。本文根据庄河市1984年1月1日至2018年12月31日的逐日降水数据计算了1个月、3个月、6个月、12个月共4个不同时间尺度下的标准化降水指数(SPI),并基于SPI对该地区近35年的年际与季节干旱演变特征进行了分析。结果表明:在年际变化方面,庄河市的SPI在2000年以前波动幅度较小,说明该地区的降水在时间上分布较为均匀;但自2000年以来,SPI序列出现较大的波峰与波谷,说明降雨的分布不均匀性有所增强;SPI的时间序列趋势线斜率为负值,说明该地区整体上呈现偏旱趋势,因此其水资源压力不断增大。在季节演变特征方面,夏季干旱和秋季干旱呈现增强趋势;秋旱的发生频率最高,而夏旱的出现频率最低。本研究结果可为庄河地区的抗旱减灾与水资源规划提供科学依据。 相似文献
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赵丽丽 《水资源开发与管理》2021,(3):34-37
本文在分析阎王鼻子水库建设前后下游水文情势变化的基础上,根据河道内生态不同需求和不同计算方法,确定水库下游河道基本生态流量和目标生态流量两种需求方案。在充分考虑大凌河流域河道外需水的前提下,研究分析了阎王鼻子水库最大程度满足河道内不同生态需水要求时的调度方案,对改善水库下游河道环境具有一定的指导意义。 相似文献
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Mengyi Chen Xiaoyang Zhu Xiaojuan Liu Caiyu Wu Canye Yu Guojian Hu Lin Chen Riyuan Chen Mondher Bouzayen Mohammed Zouine Yanwei Hao 《International journal of molecular sciences》2021,22(7)
Auxin response factors (ARFs) play important roles in various plant physiological processes; however, knowledge of the exact role of ARFs in plant responses to water deficit is limited. In this study, SlARF4, a member of the ARF family, was functionally characterized under water deficit. Real-time fluorescence quantitative polymerase chain reaction (PCR) and β-glucuronidase (GUS) staining showed that water deficit and abscisic acid (ABA) treatment reduced the expression of SlARF4. SlARF4 was expressed in the vascular bundles and guard cells of tomato stomata. Loss of function of SlARF4 (arf4) by using Clustered Regularly Interspaced Short Palindromic Repeats/Cas 9 (CRISPR/Cas 9) technology enhanced plant resistance to water stress and rehydration ability. The arf4 mutant plants exhibited curly leaves and a thick stem. Malondialdehyde content was significantly lower in arf4 mutants than in wildtype plants under water stress; furthermore, arf4 mutants showed higher content of antioxidant substances, superoxide dismutase, actual photochemical efficiency of photosystem II (PSII), and catalase activities. Stomatal and vascular bundle morphology was changed in arf4 mutants. We identified 628 differentially expressed genes specifically expressed under water deficit in arf4 mutants; six of these genes, including ABA signaling pathway-related genes, were differentially expressed between the wildtype and arf4 mutants under water deficit and unlimited water supply. Auxin responsive element (AuxRE) elements were found in these genes’ promoters indicating that SlARF4 participates in ABA signaling pathways by regulating the expression of SlABI5/ABF and SCL3, thereby influencing stomatal morphology and vascular bundle development and ultimately improving plant resistance to water deficit. 相似文献
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Rizwana Begum Syed Nabi Rupesh Tayade Adil Hussain Arjun Adhikari In-Jung Lee Gary J. Loake Byung-Wook Yun 《International journal of molecular sciences》2021,22(10)
In the last two decades, global environmental change has increased abiotic stress on plants and severely affected crops. For example, drought stress is a serious abiotic stress that rapidly and substantially alters the morphological, physiological, and molecular responses of plants. In Arabidopsis, several drought-responsive genes have been identified; however, the underlying molecular mechanism of drought tolerance in plants remains largely unclear. Here, we report that the “domain of unknown function” novel gene DUF569 (AT1G69890) positively regulates drought stress in Arabidopsis. The Arabidopsis loss-of-function mutant atduf569 showed significant sensitivity to drought stress, i.e., severe wilting at the rosette-leaf stage after water was withheld for 3 days. Importantly, the mutant plant did not recover after rewatering, unlike wild-type (WT) plants. In addition, atduf569 plants showed significantly lower abscisic acid accumulation under optimal and drought-stress conditions, as well as significantly higher electrolyte leakage when compared with WT Col-0 plants. Spectrophotometric analyses also indicated a significantly lower accumulation of polyphenols, flavonoids, carotenoids, and chlorophylls in atduf569 mutant plants. Overall, our results suggest that novel DUF569 is a positive regulator of the response to drought in Arabidopsis. 相似文献
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Ruoyi Lin Tao Zou Qiming Mei Zhengfeng Wang Mei Zhang Shuguang Jian 《International journal of molecular sciences》2021,22(9)
Canavalia rosea (bay bean), distributing in coastal areas or islands in tropical and subtropical regions, is an extremophile halophyte with good adaptability to seawater and drought. Late embryogenesis abundant (LEA) proteins typically accumulate in response to various abiotic stresses, including dehydration, salinity, high temperature, and cold, or during the late stage of seed development. Abscisic acid-, stress-, and ripening-induced (ASR) genes are stress and developmentally regulated plant-specific genes. In this study, we reported the first comprehensive survey of the LEA and ASR gene superfamily in C. rosea. A total of 84 CrLEAs and three CrASRs were identified in C. rosea and classified into nine groups. All CrLEAs and CrASRs harbored the conserved motif for their family proteins. Our results revealed that the CrLEA genes were widely distributed in different chromosomes, and all of the CrLEA/CrASR genes showed wide expression features in different tissues in C. rosea plants. Additionally, we introduced 10 genes from different groups into yeast to assess the functions of the CrLEAs/CrASRs. These results contribute to our understanding of LEA/ASR genes from halophytes and provide robust candidate genes for functional investigations in plant species adapted to extreme environments. 相似文献