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PubMed2000

[Effect of elevated CO2 concentration on photosynthesis and antioxidative enzyme activities of wheat plant grown under drought condition].

The photosynthesis and antioxidative enzyme activities of wheat plants grown in two open-top chambers with CO2 concentrations of 350 mumol.mol-1 and 700 mumol.mol-1 were examined under drought stress. The result showed that elevated CO2 concentration obviously enhanced the photosynthesis, stomatal resistance and water use efficiency, but decreased the transpiration of wheat. Doubled CO2 concentration significantly increased the activities of CAT, POD and SOD, which enhanced the abilities of antioxidative defence and drought tolerance.

Carbon Dioxide↗
PubMed2002

Integrated watershed approach for combating drought in a semi-arid region of India: the case of Jhabua watershed.

The integrated watershed management approach for the semi-arid regions of India is considered to be very important due to the inadequate availability of water resources. The drought experienced in recent years has brought on an environmental and socio-economic crisis in these regions. The role of the watershed management has been crucial and development of alternative water resources has been critically important. To overcome the isolated sectoral development planning and implementation, as was done in many of the previous land based programs in India, an integrated concept of watershed development through participatory planning and actions has been followed for combating drought in Jhabua watershed in Madhya Pradesh state, India. This research paper will look into the successful watershed management experience of our on-going research project, and appropriate watershed strategies for the Jhabua watershed.

Agriculture↗
PubMed2001

The effect of drought on the development and yielding of two different varieties of the fodder broad bean (Vicia faba minor).

A factorial experiment was performed in the fodder broad bean to analyse effects of soil drought on the development and yield components of two varieties of different morphotype: 'Nadwiślański' (traditional) and 'Tim' (determinate growth habit). Plants were grown in Mitscherlich's pots under three different soil moistures: 70%, 50% and 30% of field water capacity. The soil water shortage contributed to a considerable depression in the developmental characteristics and yield traits of both varieties. Under all conditions, the variety 'Nadwiślański yielded more seeds than did 'Tim'. The traditional variety was more resistant to drought than the new 'Tim'.

Journal Article↗
PubMed2004

[Effect of short-term drought on leaf water potential, photosynthesis and dry matter partitioning in paddy rice].

Pot experiments were conducted to study the effect of short-term drought at four rice growth stages on leaf water potential, photosynthesis and dry matter partitioning in paddy rice. The leaf water potential of rice plant under water stress was lower than that of CK, and the difference increased after midday. The predawn leaf water potential of rice plant decreased significantly when soil water content or soil water potential went down a threshold value, resulted in an obvious decline in the single leaf net photosynthetic rate. In compared with the well-watered treatment, the net photosynthetic rate under severe water stress decreased by more than 50%. The partitioning indexes of leaf, root and spike decreased, while that of stem and sheath increased after short-term drought.

Disasters↗
PubMed2004

[Simplification of crop shortage water index and its application in drought remote sensing monitoring].

Based on the principle of energy balance, the method for calculating latent evaporation was simplified, and hence, the construction of the drought remote sensing monitoring model of crop water shortage index was also simplified. Since the modified model involved fewer parameters and reduced computing times, it was more suitable for the operation running in the routine services. After collecting the concerned meteorological elements and the NOAA/AVHRR image data, the new model was applied to monitor the spring drought in Guanzhong, Shanxi Province. The results showed that the monitoring results from the new model, which also took more considerations of the effects of the ground coverage conditions and meteorological elements such as wind speed and the water pressure, were much better than the results from the model of vegetation water supply index. From the view of the computing times, service effects and monitoring results, the simplified crop water shortage index model was more suitable for practical use. In addition, the reasons of the abnormal results of CWSI > 1 in some regions in the case studies were also discussed in this paper.

Crops, Agricultural↗
PubMed2004

[Arabidopsis CBF1 in plant tolerance to low temperature and drought stresses].

Since it was established that the alteration in gene expression occur during cold acclimation, a major goal in cold acclimation research has been to identify cold-responsive genes and to determine whether they play roles in freezing tolerance. Many cold-regulated genes (COR) were isolated and characterized in Arabidopsis and other cold tolerant plant species. Studies on regulation of COR in Arabidopsis have resulted in the discovery of a family of transcriptional activators, of which, CBF1, a member of the gene family, controls expression of a battery of COR in Arabidopsis and other cold tolerant plant species. During recent years, CBF-like genes were found in the genomes of chilling-sensitive plant species such as tomato and maize. Over-expression of Arabidopsis CBF1 confers elevated tolerance to chilling and drought stresses in transgenic tomato. These results promote our effort to identify and characterize CBF-like genes to improve tolerance of chilling-sensitive plant species to chilling and drought stresses.

Acclimatization↗
PubMedDate not supplied

Managing child malnutrition in a drought affected district of Rajasthan--a case study.

Rajasthan is the largest state in the country frequently affected by droughts. The year 2002 happened to be the fifth consecutive year of drought. Almost all districts of the State were hit by it. The district of Baran located in South-East of Rajasthan has 'Sahariya' tribal population concentrated in its Kishanganj and Shahabad blocks. Press reports of starvation deaths amongst tribal children in these blocks created a stir in the local district and the State Government set ups. The paper describes an objective and professional approach to deal with the situation. Rapid nutritional assessment indicated very high prevalence of severe under weight (28.3%) and wasting (4.7%) amongst under five children. Nutrition Care Centres (NCC) were set up in selected villages to provide targeted feeding and care to these children as per WHO guidelines. Local 'Sahariya' community was involved to run these NCC. Intensive public education campaign was carried out to promote improved child caring practices and referral of malnourished children with complication to hospitals. Orientation of press and electronic media on factual details regarding the situation helped create an enabling environment to implement remedial measures. The impact of 'Nutrition Care Centres' assessed after six months was found to be positive in terms of reduction in prevalence of under nutrition in children from 66.7% to 59.6%. Successful management of severe malnutrition amongst children by workers at Nutrition Care Centes and in family settings using standard protocols led to the wide scale replication of the approach by Anganwadi centres in different district of Rajasthan. The State Government also created an additional cadre of worker called 'Sahayogini' to support Anganwadi worker and promote better child caring practices at family level.

Child Health Services↗
PubMed2006

[Physiological and biochemical indexes of drought resistance of sugarcane (Saccharum spp.)].

Through factor analysis and grey correlative degree analysis, this paper studied the relationships of sugarcane leaf relative water content (RWC), membrane lipid peroxidation metabolism, active oxygen metabolism, photosynthesis, and stalk yield with drought resistance of sugarcane. The results suggested that under drought stress, the plasma membrane permeability (PMP) and malondialdehyde (MDA) content were markedly increased, while RWC, superoxide dismutase (SOD) activity, chlorophyll (Chl) content, PS II photochemical efficiency (F(v)/ F(m)), PS II potential activity (F(v)/F(o)), variable fluorescence quenching rate (deltaF(v)/F(o)), efficiency of potential quantum conversion (deltaF(v)/F(t)), and single stalk weight (SSW) were remarkably decreased. The correlation of SSW with test indexes was decreased in the order of PMP, SOD activity, MDA content, RWC, F(v)/F(o), F(v)/F(m), Chl content, deltaF(v)/F(o) and deltaF(v)/F(t). Through factor analysis, the test indexes were divided into four common factors, among which, the indexes of photosynthesis played important roles in the first factor, RWC and the indexes of active oxygen metabolism dominated in the second factor, while SSW and Chl content played primary roles in the third and fourth factor, respectively. The grey correlative degree of SSW with other indexes was in the rank of F(v)/F(m), PMP, F(v)/F(o), RWC, MDA content, SOD activity, deltaF(v)/F(t), Chl content, and deltaF(v)/F(o).

Chlorophyll↗
PubMed1991

Nutritional assessment of children in drought-affected areas--Haiti, 1990.

From January through June 1990, a drought occurred in the Caribbean nation of Haiti. To determine whether the nutritional status of young children had been affected by drought-related reductions in food supply, in September 1990 a nutrition survey was conducted in the five departments most affected (Nord-Ouest, Nord, Nord-Est, Artibonite, and Centre) of Haiti's nine departments.

Child↗
PubMedDate not supplied

[Drought and malaria decrease in the Niayes area of Senegal].

The Niayes is geographically characterized by an alternating succession of sand dunes and wet depressions, 20 km wide, which are behind the offshore bars from Saint-Louis to Dakar. Since 1970, the area has been affected by drought. The rainfall which was around 700 mm per year before 1960 has fallen below 500 mm during the last 30 years. In 1991 it was only 350 mm and in 1992, 260 mm. The vegetation has become impoverished in the depressions which are now more and more cultivated for vegetables. Entomological, parasitological and clinical studies on malaria were carried out in 1991 and 1992 in three villages and the results were compared with data gathered from 1967 to 1968 with comparable methods. The main points concerning the evolution of malaria are listed as follows. An. funestus, which was previously the predominant malaria vector, has almost disappeared. An. gambiae has regressed ahead of its sibling species An. arabiensis, a less competent vector. These changes in vector populations have led to lower malaria transmission and consequently a decrease of the endemicity. The children parasitic index, which was between 40 to 80% according to the localities in 1967, fell to 10% or less in 1991 and 1992. Finally, the incidence of clinical cases, calculated on a cohort of 100 children was only 4% in 1992, which is very low for an African endemic country. We conclude that drought and human activities have modified the environment such that malaria endemicity has seriously decreased. However, the risk of epidemic remains with the eventual occurrence of heavy rains. Therefore a surveillance of the area is needed to prevent a future epidemic.

Animals↗
PubMed2026

Complete telomere-to-telomere genome assembly of Guazuma ulmifolia uncovers evolutionary mechanisms, drought adaptation, and flavonoid biosynthesis.

The first T2T reference genome of Guazuma ulmifolia is reported, which serves as a core genomic resource for stress adaptation research and stress-tolerant breeding in cacao wild relatives. Climate change, particularly increased incidence of drought, poses a major threat to food security. Understanding the genomic basis of environmental adaptation in crop wild relatives can provide valuable resources for improving stress resilience. Guazuma ulmifolia, a wild relative of Theobroma cacao with important ecological and medicinal value, lacks high-quality reference genomic resources. Here, we report the first telomere-to-telomere (T2T) chromosome-level genome assembly of G. ulmifolia, with a genome size of 311.31 Mb, contig N50 of 35.19 Mb, and 98.70% BUSCO completeness. Repetitive sequences constitute 27.43% of the G. ulmifolia genome, with LTR retrotransposons as the predominant class. Comparative genomic analyses revealed that genome-size variation among Malvaceae species is associated with differences in polyploidization history and TE dynamics. Ancestral karyotype reconstruction identified five lineage-specific chromosome fusion events distinguishing G. ulmifolia from T. cacao. Comparative analyses further identified tandem duplication-associated expansion of stress-related LEA and GST gene families, suggesting potential genomic features associated with stress responses. Flavonoid biosynthesis genes were largely conserved in copy number but showed tissue-specific expression patterns, providing candidate genes for investigating secondary metabolism. Together, this study establishes a high-quality T2T genome resource for exploring genome evolution, chromosome organization, and stress-related genomic features in Malvaceae.

Genome, Plant↗
PubMed2026

Genome-wide analysis of the plant-specific PLATZ gene family in Taraxacum kok-saghyz and its roles in response to drought and salt tolerance.

Abiotic stress severely limits plant growth and productivity. Taraxacum kok-saghyz Rodin (TKS), known for its environmental resilience, represents a valuable resource for identifying stress-tolerant genes to improve stress-adaptive crops. Plant AT-rich protein and zinc-binding protein (PLATZ) transcription factors serve as core regulators of plant growth, developmental processes, and adaptive responses to various stress conditions; however, they remain uncharacterized in TKS. Here, we identified 10 TksPLATZ genes through a whole-genome analysis. Phylogenetically, these genes were grouped into five distinct evolutionary branches. Promoter sequence analysis revealed multiple types of cis-acting regulatory elements that are connected with hormonal signal responses and environmental stress adaptation. Integrated analysis of transcriptome datasets and RT-qPCR validation demonstrated that TksPLATZ genes display tissue-specific expression profiles and show distinct responsive patterns to drought and salt stress treatments. Among them, TksPLATZ1, TksPLATZ2 and TksPLATZ7 were markedly induced under both stressors and were selected for further functional study. We demonstrated that TksPLATZ1, TksPLATZ2 and TksPLATZ7 localize to the cell nucleus and act as transcriptional activators and repressors, respectively. Phenotypic data from overexpression experiments in plants confirm that heterologous expression of TksPLATZ1, TksPLATZ2, and TksPLATZ7 enhances the tolerance of Arabidopsis to salt and osmotic stress. These findings provide valuable genetic resources for improving plant tolerance to environmental stresses.

Salt Tolerance↗
PubMed2026

Evolution and Expression Divergence of Legume PAL Genes Suggest Associations with Drought Response and Root Nodule Development.

Comparative genomic analyses provide insight into the mechanisms underlying gene-family evolution and crop adaptation. Here, we used the legume phenylalanine ammonia-lyase (PAL) gene family as a model and integrated pan-genomic, phylogenetic, molecular evolutionary, duplication-mode, and transcriptomic analyses, while developing GFtool for gene family identification. Across 45 genomes, we identified 302 PAL genes and classified them into five Groups. Groups 1-3 represented ancient lineages shared with outgroups, whereas Groups 4 and 5 were legume-specific. Molecular-clock analyses placed the divergence of Group 2 near the Paleocene-Eocene transition, while Groups 4 and 5 diversified from the middle Eocene to the early Oligocene. WGD/segmental duplication broadly contributed to PAL copy-number expansion, whereas tandem duplication was enriched in Group 5 of Papilionoideae. Group 2 genes showed drought-induced expression, whereas Group 5 genes were associated with early root nodule development. GFtool provides a scalable framework for gene-family studies.

Fabaceae↗
PubMed2006

Mapping the proteome of poplar and application to the discovery of drought-stress responsive proteins.

Poplar is the first forest tree genome to be decoded. As an initial step to the comprehensive analysis of poplar proteome, we described reference 2-D-maps for eight tissues/organs of the plant, and the functional characterization of some proteins. A total of 398 proteins were excised from the gels. About 91.2% were identified by nanospray LC-MS/MS, based on comparison with 260,000 Populus sp. ESTs. In comparison, reliable PMFs were obtained for only 51% of the spots by MALDI-TOF-MS, from which 43% (83 spots) positively matched gene models of the Populus trichocarpa genome sequence. Among these 83 spots, 58% matched with the same proteins as identified by LC-MS/MS, 21.7% with unknown function proteins and 19.3% with completely different functions. In the second phase, we studied the effect of drought stress on poplar root and leaf proteomes. The function of up- and down-regulated proteins is discussed with respect to the physiological response of the plants and compared with transcriptomic data. Some important clues regarding the way poplar copes with water deficit were revealed.

Databases, Protein↗
PubMed1995

Drought, heat and salt stress induce the expression of a citrus homologue of an atypical late-embryogenesis Lea5 gene.

In a search for genes that are induced in citrus cell suspension in response to salt stress, a cDNA clone with high homology to cotton Lea5 gene was isolated. Data base analysis of the protein deduced from the nucleotide sequence indicates that, like in cotton, the protein from citrus contains regions with significant hydropathic character. The gene, designated C-Lea5, is expressed in citrus leaves as well as cell suspension. The steady-state level of C-Lea5 is increased in cell suspension that is grown in the presence of 0.2 M NaCl. This phenomenon is also observed in leaves of citrus plants irrigated with NaCl and in citrus seedlings which are exposed to drought and heat stress. We suggest that the osmotic stress resulted from elevated level of salt is responsible for the increase in the level of C-Lea5.

Amino Acid Sequence↗
PubMed1993

Arabidopsis thaliana cor15b, an apparent homologue of cor15a, is strongly responsive to cold and ABA, but not drought.

We previously described a cold-regulated (cor) gene from Arabidopsis thaliana, cor15a (formerly cor15), that encodes a 15 kDa polypeptide that is targeted to chloroplasts (C. Lin and M. Thomashow, Plant Physiol 99 (1992): 519-525). Here we describe an apparent homologue of cor15a, cor15b. cor15b is located immediately downstream from cor15a (within 1 kb) and has the same relative 5' to 3' orientation as cor15a. The predicted coding regions for the two genes are 82% identical at the nucleic acid sequence level. Transcripts for cor15b, like those of cor15a, increase dramatically in response to low temperature and exogenous application of ABA. However, only cor15a transcripts accumulate to high levels in response to drought. The cor15a/cor15b gene pair is the third case in which A. thaliana cold-regulated genes have been found to exist as tandem gene pairs with the members of each pair being differentially regulated.

Abscisic Acid↗
PubMed1994

The 5'-region of Arabidopsis thaliana cor15a has cis-acting elements that confer cold-, drought- and ABA-regulated gene expression.

Previous nuclear run-on experiments indicated that the cor15a (cold-regulated) gene of Arabidopsis thaliana L. (Heyn) has a cold-inducible promoter (Hajela et al., Plant Physiol 93: 1246-1252, 1990). The data presented here indicate that the 5' region of cor15a between nucleotides -305 and +78 (relative to the start of transcription) contains a cis-acting element(s) that can impart cold-regulated gene expression. Histochemical staining experiments indicated that the cor15a promoter is inactive, or very weakly active, in most of the tissues and organs of plants grown at normal temperature and that it becomes activated throughout most of the plant in response to low temperature. Notable exceptions to this general pattern include constitutive activity of the promoter in anthers of control grown plants and apparent inactivity of the promoter in the roots and ovaries of cold-treated plants. Histochemical staining experiments also indicated that low temperature regulation of cor15a does not involve the synthesis of a regulatory molecule that can spread throughout the plant and induce cor gene expression at normal growth temperature. Finally, gene fusion experiments indicated that the 5' region of cor15a between nucleotides -305 and +78, in addition to imparting cold-regulated gene expression, can impart ABA- and drought-regulated gene expression.

Abscisic Acid↗
PubMed1994

Characterization and differential expression of dhn/lea/rab-like genes during cold acclimation and drought stress in Arabidopsis thaliana.

We have characterized cDNAs for two new dhn/lea/rab (dehydrin, late embryogenesis-abundant, responsive to ABA)-related genes from Arabidopsis thaliana. The two genes were strongly induced in plants exposed to low temperature (4 degrees C) and were accordingly designated lti45 and lti30 (low temperature-induced). The lti45 gene product contains the conserved serine stretch and three lysine-rich repeats characteristic of DHN/LEA/RAB proteins and is very similar to another low temperature-responsive protein of A. thaliana, COR47 [17]. Both proteins have the same repeat structure and an overall amino acid identity of 64%. This structural similarity of the proteins and the tandem array of the genes suggest that this gene pair arose through a duplication. The other polypeptide, LTI30, consists of several lysine-rich repeats, a structure found in CAP85, a low temperature- and water stress-responsive protein in spinach [41] and similar proteins found in wheat [20]. The expression pattern of the five dhn/lea/rab-related genes (cor47, dhnX, lti30, lti45 and rab18) identified so far in A. thaliana, was characterized in plants exposed to low temperature, drought and abscisic acid (ABA). Expression of both lti30 and lti45 was mainly responsive to low temperature similar to cor47. The lti45 and lti30 genes show only a weak response to ABA in contrast to cor47, which is moderately induced by this hormone. The three genes were also induced in severely water-stressed plants although the expression of lti30 and lti45 was rather low. In contrast to these mainly low temperature-induced genes, the expression of rab18 was strongly induced both in water-stressed and ABA-treated plants but was only slightly responsive to cold. The dhnX gene showed a very different expression pattern. It was not induced with any of the treatments tested but exhibited a significant constitutive expression. The low-temperature induction of the genes in the first group, lti30 and lti45, is ABA-independent, deduced from experiments with the ABA-deficient (aba-1) and ABA-insensitive (abil) mutants of A. thaliana, whereas the induction of rab18 is ABA-mediated. The expression of dhnX was not significantly affected in the ABA mutants.

Abscisic Acid↗