scholarly journals Overexpression of Bacterial mtlD Gene in Peanut Improves Drought Tolerance through Accumulation of Mannitol

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Tengale Dipak Bhauso ◽  
Thankappan Radhakrishnan ◽  
Abhay Kumar ◽  
Gyan Prakash Mishra ◽  
Jentilal Ramjibhai Dobaria ◽  
...  
Keyword(s):  
Water Deficit ◽  
Radical Scavenging ◽  
Water Deficit Stress ◽  
Gene Coding ◽  
Global Environmental ◽  
Relative Water ◽  
Transgenic Lines ◽  
Improved Performance ◽  
Radical Scavenging Ability ◽  
Response To Water

In the changing global environmental scenarios, water scarcity and recurrent drought impose huge reductions to the peanut (Arachis hypogaea L.) crop yield. In plants, osmotic adjustments associated with efficient free radical scavenging ability during abiotic stress are important components of stress tolerance mechanisms. Mannitol, a compatible solute, is known to scavenge hydroxyl radicals generated during various abiotic stresses, thereby conferring tolerance to water-deficit stress in many plant species. However, peanut plant is not known to synthesize mannitol. Therefore, bacterial mtlD gene coding for mannitol 1-phosphate dehydrogenase under the control of constitutive promoter CaMV35S was introduced and overexpressed in the peanut cv. GG 20 using Agrobacterium tumefaciens-mediated transformation. A total of eight independent transgenic events were confirmed at molecular level by PCR, Southern blotting, and RT-PCR. Transgenic lines had increased amount of mannitol and exhibited enhanced tolerance in response to water-deficit stress. Improved performance of the mtlD transgenics was indicated by excised-leaf water loss assay and relative water content under water-deficit stress. Better performance of transgenics was due to the ability of the plants to synthesize mannitol. However, regulation of mtlD gene expression in transgenic plants remains to be elucidated.

Relationships between physiological traits and productivity of sugarcane in response to water deficit

2012 ◽  
Vol 152 (1) ◽  
pp. 104-118 ◽  
Author(s):  
M. DE A. SILVA ◽  
J. L. JIFON ◽  
J. A. G. DA SILVA ◽  
C. M. DOS SANTOS ◽  
V. SHARMA
Keyword(s):  
Water Deficit ◽  
Field Studies ◽  
Water Deficit Stress ◽  
Chlorophyll Contents ◽  
Physiological Variables ◽  
Drought Tolerant ◽  
Relative Water ◽  
Leaf Relative Water Content ◽  
Sugarcane Productivity ◽  
Response To Water

SUMMARYThe relationships between physiological variables and sugarcane productivity under water deficit conditions were investigated in field studies during 2005 and 2006 in Weslaco, Texas, USA. A total of 78 genotypes and two commercial varieties were studied, one of which was drought-tolerant (TCP93-4245) and the other drought-sensitive (TCP87-3388). All genotypes were subjected to two irrigation regimes: a control well-watered treatment (wet) and a moderate water-deficit stress (dry) treatment for a period of 90 days. Maximum quantum efficiency of photosystem II (Fv/Fm), estimated chlorophyll content (SPAD index), leaf temperature (LT), leaf relative water content (RWC) and productivity were measured. The productivity of all genotypes was, on average, affected negatively; however, certain genotypes did not suffer significant reduction. Under water deficit, the productivity of the genotypes was positively and significantly correlated with Fv/Fm, SPAD index and RWC, while LT had a negative correlation. These findings suggest that genotypes exhibiting traits of high RWC values, high chlorophyll contents and high photosynthetic radiation use efficiency under low moisture availability should be targeted for selection and variety development in programmes aimed at improving sugarcane for drought prone environments.

scholarly journals Trigonelline Accumulation in Leaves of Panicum virgatum Seedlings

2014 ◽  
Vol 9 (8) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Lauren M. Schwartz ◽  
Andrew J. Wood ◽  
David J. Gibson
Keyword(s):  
Water Deficit ◽  
Tallgrass Prairie ◽  
Panicum Virgatum ◽  
Water Deficit Stress ◽  
Significant Difference ◽  
Moisture Treatment ◽  
Relative Water ◽  
Tallgrass Prairies ◽  
Response To Water ◽  
Physiological Markers

Panicum virgatum is a dominant, native, perennial species found in the tallgrass prairie. In this study, we report the biosynthesis and accumulation of trigonelline (TRG) in leaves of P. virgatum in response to water-deficit stress. Once established, half of the seedlings underwent a drought stress treatment while the other half were watered daily (control). Relative water content (RWC) and trigonelline (TRG) concentrations were determined. RWC showed an interaction between moisture treatment and time, in which upland cultivars had the highest mean RWC compared with the lowland cultivars. The moisture treatments showed a significant difference in TRG concentration across all P. virgatum cultivars, which ranged from 0.5–31.8 μg/gFW−1. There was a divergence in TRG accumulation between upland and lowland cultivars in relation to RWC. This study is the first to report TRG accumulation in the grass P. virgatum, and to test for differences in TRG with respect to water-deficit stress among cultivars. The effect of soil moisture levels on cultivars may be important in making an informed selection and the response of P. virgatum and other dominant grasses should be considered as a potential filter in tallgrass prairies for restoration. Physiological markers such as TRG and RWC can aid in this decision making process.

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

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

Physio-morphological traits and osmoregulation strategies of hybrid maize (Zea mays) at the seedling stage in response to water-deficit stress

PROTOPLASMA ◽  
2021 ◽  
Author(s):  
Piyanan Pipatsitee ◽  
Cattarin Theerawitaya ◽  
Rujira Tiasarum ◽  
Thapanee Samphumphuang ◽  
Harminder Pal Singh ◽  
...  
Keyword(s):  
Zea Mays ◽  
Water Deficit ◽  
Morphological Traits ◽  
Seedling Stage ◽  
Water Deficit Stress ◽  
Hybrid Maize ◽  
Response To Water

Field Crop Response to Water Deficit Stress: Assessment Through Crop Models

2018 ◽  
pp. 287-315
Author(s):  
Rajkumar Dhakar ◽  
M. A. Sarath Chandran ◽  
Shivani Nagar ◽  
V. Visha Kumari ◽  
A. V. M. Subbarao ◽  
...  
Keyword(s):  
Water Deficit ◽  
Water Deficit Stress ◽  
Field Crop ◽  
Crop Response ◽  
Stress Assessment ◽  
Crop Models ◽  
Response To Water

Co-expression of xerophyte Zygophyllum xanthoxylum ZxNHX and ZxVP1-1 enhances salt and drought tolerance in transgenic Lotus corniculatus by increasing cations accumulation

2014 ◽  
Vol 41 (2) ◽  
pp. 203 ◽  
Author(s):  
Ai-Ke Bao ◽  
Yan-Wen Wang ◽  
Jie-Jun Xi ◽  
Chen Liu ◽  
Jin-Lin Zhang ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Water Deficit ◽  
Membrane Damage ◽  
Lotus Corniculatus ◽  
Shoot Biomass ◽  
Water Deficit Stress ◽  
Arid Environments ◽  
Salt And Drought Tolerance ◽  
Zygophyllum Xanthoxylum ◽  
Transgenic Lines

Lotus corniculatus L. is an important legume for forage, but is sensitive to salinity and drought. To develop salt- and drought-resistant L. corniculatus, ZxNHX and ZxVP1-1 genes encoding tonoplast Na+/H+ antiporter and H+-pyrophosphatase (H+-PPase) from a succulent xerophyte Zygophyllum xanthoxylum L., which is well adapted to arid environments through accumulating Na+ in its leaves, were transferred into this forage. We obtained the transgenic lines co-expressing ZxNHX and ZxVP1-1 genes (VX) as well as expressing ZxVP1-1 gene alone (VP). Compared with wild-type, both VX and VP transgenic lines grew better at 200 mM NaCl, and also exhibited higher tolerance and faster recovery from water-deficit stress: these performances were associated with more Na+, K+ and Ca2+ accumulation in their leaves and roots, which caused lower leaf solute potential and thus retained more water. Moreover, the transgenic lines maintained lower relative membrane permeability and higher net photosynthesis rate under salt or water-deficit stress. These results indicate that expression of tonoplast Na+/H+ antiporter and H+-PPase genes from xerophyte enhanced salt and drought tolerance of L. corniculatus. Furthermore, compared with VP, VX showed higher shoot biomass, more cations accumulation, higher water retention, lesser cell membrane damage and higher photosynthesis capacity under salt or water-deficit condition, suggesting that co-expression of ZxVP1-1 and ZxNHX confers even greater performance to transgenic L. corniculatus than expression of the single ZxVP1-1.

scholarly journals Changes in carbohydrates accumulation in Viguiera discolor Baker in response to water deficit

Hoehnea ◽  
2019 ◽  
Vol 46 (4) ◽  
Author(s):  
Rodrigo Fazani Esteves Sanches ◽  
Ana Paula Oliveira da Silva ◽  
Vanessa Pires da Costa ◽  
Maria Ângela Machado de Carvalho ◽  
Emerson Alves da Silva
Keyword(s):  
Water Deficit ◽  
Osmotic Adjustment ◽  
Water Status ◽  
Soluble Sugars ◽  
Water Suppression ◽  
Adaptive Responses ◽  
Close Relationship ◽  
Relative Water ◽  
Influence Of Water ◽  
Response To Water

ABSTRACT Water stress is an environmental factor that can regulate growth, limit production and lead to physiological and biochemical changes. Plants present a series of adaptive responses to drought, such as osmotic adjustment, in which carbohydrates play an important role. To evaluate the influence of water deficit on carbohydrates accumulation in V. discolor, the plants were divided into two groups: daily watering and water suppression for 14 days being re-watering after this period. Leaves and roots were collected at 0, 3, 6, 9, 12, 15 and 18 days, for ecophysiological and biochemical analyzes. Variations in carbohydrate contents in V. discolor showed a close relationship with changes in the plant water status, with higher concentrations of soluble sugars, total fructans, oligosaccharides, reducing sugars coinciding with the lower values of soil moisture and leaf water potentials and relative water content. In the tuberous roots, there is an increase in carbohydrate concentrations after re-watering. The increase of these low molecular weight carbohydrates is involved in osmotic adjustment and therefore acts to protect against dehydration.

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