Performance of Hevea brasiliensis under drought conditions on osmoregulation and antioxidant activity through evaluation of vacuolar invertase and reducing sugars

Rubber tree cultivation is limited in many regions by abiotic factors such as drought. We investigated the biochemical mechanisms responsible for responses to, and recovery from, drought conditions during the establishment phase of four high latex producing rubber tree clones (RRIM600, IAC40, PR255 and GT1). Five-month-old plants were exposed to 32 days of water restriction, followed by 15 days of soil rehydration. Leaf area, as well as their osmolyte accumulations, saccharolytic enzyme activity, and oxidative stress markers, were accompanied. Although clones IAC40 and PR255 responded more precociously to drought conditions, halting leaf expansion before clones GT1 and RRIM600, they demonstrated slow recuperation after reestablishing irrigation. The greater tolerances of clones RRIM600 and GT1 to drought conditions were related to greater vacuolar invertase (VINV) activity in their leaves, which guaranteed more significant accumulations of vacuolar reducing sugars (RS). Similar to RS, glycine betaine accumulations were related to osmoprotection and to reducing oxidative damage (lipidic peroxidation) caused by water deficit conditions. The observed decreases in cytosol neutral invertase (AINV) and cell wall insoluble invertase (CWINV) activities, which resulted in cytosol hexose decreases, may be related to increases in antioxidant enzyme (superoxide dismutase and ascorbate peroxidase) activities in the leaves in response to water deficit conditions. As such, the introduction of specific sugars (RS) and the modulation of key carbon metabolism enzymes, such as VINV, are promising strategies for promoting drought tolerance in rubber tree clones.

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Effects of Water Regime on the Structure of Roots and Stems of Durum Wheat (Triticum durum Desf.)

Journal of Botany ◽

10.1155/2014/703874 ◽

2014 ◽

Vol 2014 ◽

pp. 1-7 ◽

Cited By ~ 3

Author(s):

Amina Labdelli ◽

Ahmed Adda ◽

Youcef Halis ◽

Samira Soualem

Keyword(s):

Durum Wheat ◽

Water Deficit ◽

Adventitious Roots ◽

Structural Changes ◽

Abiotic Factors ◽

Anatomical Variations ◽

Limiting Factors ◽

Primary Xylem ◽

Triticum Durum Desf ◽

Response To Water

Yield improvement of durum wheat is considerably limited by the expression of environmental abiotic factors. Water deficits are one of these limiting factors. Plants develop various strategies to tolerate the effects of water deficit. Some of such mechanisms might occur in the root and stem systems. The present study aimed to investigate some anatomical traits contributing to the drought tolerance in the durum wheat. The anatomical variations of the meristem of roots and stems, as a response to water deficit, were evaluated. The results indicated that the enhancement of the intensity of water deficit was accompanied by profound structural changes in the piliferous zone of roots. Water deficit caused a significant decrease in the diameter of the newly formed adventitious roots, which can be explained by a reduction in the thickness of the cortical parenchyma, through the reduction of cell size. This action was usually a contrary effect in the principal adventitious roots. The study also showed that increasing the intensity of water deficit reduced the diameter of vessels in the primary xylem, thereby increasing the hydraulic resistance of roots and lowering the flow of sap.

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Biochemical changes in black oat plants in response to water deficit under different temperatures

Semina Ciências Agrárias ◽

10.5433/1679-0359.2021v42n5p2685 ◽

2021 ◽

Vol 42 (5) ◽

pp. 2685-2702

Author(s):

Altamara Viviane de Souza Sartori ◽

◽

Carolina Maria Gaspar de Oliveira ◽

Claudemir Zucareli ◽

◽

...

Keyword(s):

Water Deficit ◽

Ascorbate Peroxidase ◽

Abiotic Factors ◽

Biochemical Changes ◽

Average Temperature ◽

Plastic Bags ◽

Different Temperatures ◽

Oat Seeds ◽

Response To Water ◽

Wilting Point

The black oat (Avena strigosa Schreb.) stands out as a forage of great importance in Brazilian agriculture. However, the productivity and quality of this forage can be affected by abiotic factors, such as temperature and water availability, which affect the physiological processes and facilitate the accumulation of free radicals (reactive oxygen species - ROS). Thus, the objective of this study was to understand the biochemical changes in black oat plants subjected to water deficit at different temperatures. Experiments were conducted in a greenhouse in two experimental periods, which presented an average temperature of 20 °C and 24 °C, respectively. Black oat seeds, of the variety IAPAR 61, were sown in pots and the plants were irrigated for 60 days. After which, the pots were covered with plastic bags and the irrigation was suspended. The analyses were carried out in five periods of evaluation - M1: plants before the suspension of irrigation, M2: plants at the first wilting point, M3: three days after plastic removal and irrigation return, M4: four days after M3 and before the second suspension of irrigation, and M5: the second wilting point. The levels of total protein and malondialdehyde (MDA), and the activity of the enzymes catalase (CAT) and ascorbate peroxidase (APX), were analyzed. The experimental design was completely randomized, with six replications, in a factorial scheme of average temperature × water management × periods of evaluation, and the means were compared by Tukey’s test at 5%. In response to water deficiency and temperature increase, black oat plants increased their levels of total soluble proteins, and there was greater lipid peroxidation due to the increase in malondialdehyde content. There was no change in the activity of the enzymes catalase and ascorbate peroxidase under water deficit, and these activities decreased with increasing temperature.

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Differential response to water deficit stress and shade in two wheat (Triticum durum Desf.) cultivars: growth, water relations, osmolyte accumulation and photosynthetic pigments

Pakistan Journal of Botany ◽

10.30848/pjb2019-4(4) ◽

2019 ◽

Vol 51 (4) ◽

Cited By ~ 1

Author(s):

Fatma Gharbi ◽

Asma Guizani ◽

Lobna Zribi ◽

Hela Ben Ahmed ◽

Florent Mouillot

Keyword(s):

Water Deficit ◽

Water Relations ◽

Photosynthetic Pigments ◽

Triticum Durum ◽

Differential Response ◽

Water Deficit Stress ◽

Osmolyte Accumulation ◽

Triticum Durum Desf ◽

Response To Water

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Tissue specificity of expression of heat shock gene ATHSP70-10 in Arabidopsis thaliana seedlings under normal and stress conditions

Vìsnik Harkìvsʹkogo nacìonalʹnogo agrarnogo unìversitetu. Serìâ Bìologiâ ◽

10.35550/vbio2020.03.037 ◽

2020 ◽

Vol 2020 (3) ◽

pp. 37-47

Author(s):

L.Ye. Kozeko ◽

◽

E.L. Kordyum ◽

Keyword(s):

Arabidopsis Thaliana ◽

Heat Shock ◽

Water Deficit ◽

Tissue Specificity ◽

Abiotic Factors ◽

Root Apex ◽

Stress Conditions ◽

Heat Shock Gene ◽

Organ Specificity ◽

Pcr Analysis

Mitochondrial heat shock proteins of HSP70 family support protein homeostasis in mitochondria under normal and stress conditions. They provide folding and complex assembly of proteins encoded by mitochondrial genome, as well as import of cytosolic proteins to mitochondria, their folding and protection against aggregation. There are reports about organ-specificity of mitochondrial HSP70 synthesis in plants. However, tissue specificity of their functioning remains incompletely characterized. This problem was studied for mitochondrial AtHSP70-10 in Arabidopsis thaliana seedlings using a transgenic line with uidA signal gene under normal conditions, as well as high temperature and water deficit. Under normal conditions, histochemical GUS-staining revealed the expression of AtHSP70-10 in cotyledon and leaf hydathodes, stipules, central cylinder in root differentiation and mature zones, as well as weak staining in root apex and root-shoot junction zone. RT-PCR analysis of wild-type seedlings exposed to 37°C showed rapid upregulation of AtHSP70-10, which reached the highest level within 2 h. In addition, the gradual development of water deficit for 5 days caused an increase in transcription of this gene, which became more pronounced after 3 days and reached a maximum after 5 days of dehydration. Histochemical analysis showed complete preservation of tissue localization of AtHSP70-10 expression under both abiotic factors. The data obtained indicate the specific functioning of mitochondrial chaperone AtHSP70-10 in certain plant cellular structures.

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Overexpression of MdATG8i improves water use efficiency in transgenic apple by modulating photosynthesis, osmotic balance, and autophagic activity under moderate water deficit

Horticulture Research ◽

10.1038/s41438-021-00521-2 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Xin Jia ◽

Ke Mao ◽

Ping Wang ◽

Yu Wang ◽

Xumei Jia ◽

...

Keyword(s):

Water Use Efficiency ◽

Water Deficit ◽

Water Use ◽

Photosynthetic Capacity ◽

Critical Role ◽

Drought Conditions ◽

Moderate Drought ◽

Use Efficiency ◽

Autophagic Activity

AbstractWater deficit is one of the major limiting factors for apple (Malus domestica) production on the Loess Plateau, a major apple cultivation area in China. The identification of genes related to the regulation of water use efficiency (WUE) is a crucial aspect of crop breeding programs. As a conserved degradation and recycling mechanism in eukaryotes, autophagy has been reported to participate in various stress responses. However, the relationship between autophagy and WUE regulation has not been explored. We have shown that a crucial autophagy protein in apple, MdATG8i, plays a role in improving salt tolerance. Here, we explored its biological function in response to long-term moderate drought stress. The results showed that MdATG8i-overexpressing (MdATG8i-OE) apple plants exhibited higher WUE than wild-type (WT) plants under long-term moderate drought conditions. Plant WUE can be increased by improving photosynthetic efficiency. Osmoregulation plays a critical role in plant stress resistance and adaptation. Under long-term drought conditions, the photosynthetic capacity and accumulation of sugar and amino acids were higher in MdATG8i-OE plants than in WT plants. The increased photosynthetic capacity in the OE plants could be attributed to their ability to maintain optimal stomatal aperture, organized chloroplasts, and strong antioxidant activity. MdATG8i overexpression also promoted autophagic activity, which was likely related to the changes described above. In summary, our results demonstrate that MdATG8i-OE apple lines exhibited higher WUE than WT under long-term moderate drought conditions because they maintained robust photosynthesis, effective osmotic adjustment processes, and strong autophagic activity.

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Physiological and transcriptional response to drought stress among bioenergy grass Miscanthus species

Biotechnology for Biofuels ◽

10.1186/s13068-021-01915-z ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Jose J. De Vega ◽

Abel Teshome ◽

Manfred Klaas ◽

Jim Grant ◽

John Finnan ◽

...

Keyword(s):

Drought Stress ◽

Water Supply ◽

Biomass Yield ◽

Transcriptional Response ◽

Biomass Productivity ◽

Differentially Expressed ◽

Model Organisms ◽

Drought Conditions ◽

Multiple Copies ◽

Response To Water

Abstract Background Miscanthus is a commercial lignocellulosic biomass crop owing to its high biomass productivity, resilience and photosynthetic capacity at low temperature. These qualities make Miscanthus a particularly good candidate for temperate marginal land, where yields can be limited by insufficient or excessive water supply. Differences in response to water stress have been observed among Miscanthus species, which correlated to origin. In this study, we compared the physiological and molecular responses among Miscanthus species under excessive (flooded) and insufficient (drought) water supply in glasshouse conditions. Results A significant biomass loss was observed under drought conditions in all genotypes. M. x giganteus showed a lower reduction in biomass yield under drought conditions compared to the control than the other species. Under flooded conditions, biomass yield was as good as or better than control conditions in all species. 4389 of the 67,789 genes (6.4%) in the reference genome were differentially expressed during drought among four Miscanthus genotypes from different species. We observed the same biological processes were regulated across Miscanthus species during drought stress despite the DEGs being not similar. Upregulated differentially expressed genes were significantly involved in sucrose and starch metabolism, redox, and water and glycerol homeostasis and channel activity. Multiple copies of the starch metabolic enzymes BAM and waxy GBSS-I were strongly up-regulated in drought stress in all Miscanthus genotypes, and 12 aquaporins (PIP1, PIP2 and NIP2) were also up-regulated in drought stress across genotypes. Conclusions Different phenotypic responses were observed during drought stress among Miscanthus genotypes from different species, supporting differences in genetic adaption. The low number of DEGs and higher biomass yield in flooded conditions supported Miscanthus use in flooded land. The molecular processes regulated during drought were shared among Miscanthus species and consistent with functional categories known to be critical during drought stress in model organisms. However, differences in the regulated genes, likely associated with ploidy and heterosis, highlighted the value of exploring its diversity for breeding.

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Tolerance mechanisms in maize identified through phenotyping and transcriptome analysis in response to water deficit stress

Physiology and Molecular Biology of Plants ◽

10.1007/s12298-021-01003-4 ◽

2021 ◽

Author(s):

Mandapaka Maheswari ◽

Yellisetty Varalaxmi ◽

Basudeb Sarkar ◽

Nakka Ravikumar ◽

Maddi Vanaja ◽

...

Keyword(s):

Water Deficit ◽

Transcriptome Analysis ◽

Water Deficit Stress ◽

Tolerance Mechanisms ◽

Response To Water

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Candidate genes and SNPs associated with stomatal conductance under drought stress in Vitis

BMC Plant Biology ◽

10.1186/s12870-020-02739-z ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Massimiliano Trenti ◽

Silvia Lorenzi ◽

Pier Luigi Bianchedi ◽

Daniele Grossi ◽

Osvaldo Failla ◽

...

Keyword(s):

Drought Stress ◽

Stomatal Conductance ◽

Candidate Genes ◽

Water Deficit ◽

Genetic Basis ◽

Phenotypic Diversity ◽

Snp Array ◽

A Genome ◽

Raffinose Synthase ◽

Response To Water

Abstract Background Understanding the complexity of the vine plant’s response to water deficit represents a major challenge for sustainable winegrowing. Regulation of water use requires a coordinated action between scions and rootstocks on which cultivars are generally grafted to cope with phylloxera infestations. In this regard, a genome-wide association study (GWAS) approach was applied on an ‘ad hoc’ association mapping panel including different Vitis species, in order to dissect the genetic basis of transpiration-related traits and to identify genomic regions of grape rootstocks associated with drought tolerance mechanisms. The panel was genotyped with the GrapeReSeq Illumina 20 K SNP array and SSR markers, and infrared thermography was applied to estimate stomatal conductance values during progressive water deficit. Results In the association panel the level of genetic diversity was substantially lower for SNPs loci (0.32) than for SSR (0.87). GWAS detected 24 significant marker-trait associations along the various stages of drought-stress experiment and 13 candidate genes with a feasible role in drought response were identified. Gene expression analysis proved that three of these genes (VIT_13s0019g03040, VIT_17s0000g08960, VIT_18s0001g15390) were actually induced by drought stress. Genetic variation of VIT_17s0000g08960 coding for a raffinose synthase was further investigated by resequencing the gene of 85 individuals since a SNP located in the region (chr17_10,497,222_C_T) was significantly associated with stomatal conductance. Conclusions Our results represent a step forward towards the dissection of genetic basis that modulate the response to water deprivation in grape rootstocks. The knowledge derived from this study may be useful to exploit genotypic and phenotypic diversity in practical applications and to assist further investigations.

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