scholarly journals Overexpression of OsHox-6 Gene Enhanced Tiller Number in Rice But Induced Yield Penalty

2019 ◽  
Vol 23 (1) ◽  
pp. 30
Author(s):  
Syamsidah Rahmawati ◽  
Chairunnisa Chairunnisa ◽  
Eva Erdayani ◽  
Satya Nugroho ◽  
Amy Estiati
Keyword(s):  
Water Stress ◽  
Transgenic Plants ◽  
Leucine Zipper ◽  
Extra Copy ◽  
Real Time Quantitative Pcr ◽  
Phenotypic Alteration ◽  
Relative Water ◽  
Transgenic Lines ◽  
Response To Water ◽  
Yield Penalty

OsHox-6, belongs to the transcription factor homeodomain leucine zipper (HD-Zip) protein sub-family I, has unknown function. This study was aimed to characterize the phenotypes of two homozygous transgenic rice lines (S29-62-2 and S.40.4-158-1) containing an extra copy of OsHox-6 gene under the control of a rice constitutive promoter, OsLEA3, and to evaluate their tolerance to water stress. A real-time quantitative PCR (qRT-PCR) showed that the transcript expression of OsHox-6 gene in the transgenic lines increased 5-10 folds under a normal irrigation and 10-20 folds after exposure to water stress conditions as compared to its wild type control. Transgenic plants overexpressing OsHox-6 exhibited phenotypic alteration at the normal irrigation by inducing tiller formation, suggesting a decrease in the apical dominance. Transgenic plants also showed significant enhancement in the total grain number, however, the number of empty grains  also increased significantly (~16-22%).  After imposed to the water stress, the number of empty grains in the transgenic lines was even higher (up to 83% in average). Furthermore, observations on the water loss rates, relative water contents and drought resistance indices (DRI) suggested that the overexpression of OsHox-6 did not significantly increase tolerance to water stress.  Further research is required to reveal the detailed mechanisms of OsHox-6 in response to water and other abiotic stresses.

Inhibition of Flowering in Lolium temulentum L. By Water Stress: a Role for Abscisic Acid

1977 ◽  
Vol 4 (2) ◽  
pp. 225 ◽  
Author(s):  
RW King ◽  
LT Evans
Keyword(s):  
Abscisic Acid ◽  
Water Stress ◽  
Long Day ◽  
Relative Water ◽  
The One ◽  
Floral Evocation ◽  
Leaf Photosynthetic Rate ◽  
Response To Water ◽  
Aba Content ◽  
High Intensity Light

A brief, 8-h water stress during the induction of flowering in L. temulentum reduces the flowering response, the more so the greater the stress. Water stress also affected leaf photosynthetic rate, relative water content of leaves and leaf elongation. Water stress was most inhibitory to flowering when applied during the period of high-intensity light at the beginning of the one long day. The abscisic acid (ABA) content of leaves increased up to 30-fold during the imposition of water stress and fell rapidly after stress was relieved, regardless of when the stress was imposed. The greater the stress, the higher was the level of ABA in leaves and the greater was the inhibition of flowering. The ABA content of apices also rose in response to water stress, in some cases during the stress treatment but usually 8-22 h later. Flowering was inhibited when apical ABA contents were high at the end of the long day. Although water stress may influence the flowering of plants in several ways, these experiments suggest that water stress during the long day induction of L. temulentum inhibits flowering by raising the content of ABA at the shoot apex during floral evocation.

Proline Analogues in Melaleuca Species: Response of Melaleuca lanceolata and M. uncinata to Water Stress and Salinity

1987 ◽  
Vol 14 (6) ◽  
pp. 669 ◽  
Author(s):  
BP Naidu ◽  
GP Jones ◽  
LG Paleg ◽  
A Poljakoff-Mayber
Keyword(s):  
Water Stress ◽  
Osmotic Adjustment ◽  
Osmotic Potential ◽  
Compatible Solutes ◽  
Species Response ◽  
Laboratory Conditions ◽  
Relative Water ◽  
Response To Water ◽  
First Time

Fifteen species of Melaleuca and two species of Callistemon from the field were examined to determine whether they accumulated nitrogen-containing compatible solutes and, if so, which. In addition to L-proline, N-methyl-L-proline (MP) (isolated for the first time from plants), trans-4-hydroxy-N-methyl- L-proline (MHP), and N, N'-dimethyl-trans-4-hydroxy-L-proline (DHP) were found in various combinations in the 15 Melaleuca species. M. lanceolata seedlings were subjected to water or salinity stress and M. uncinata to water stress under laboratory conditions. In both species significant reductions in leaf water potential (Ψw), osmotic potential (Ψs), turgor potential (Ψp), and relative water content (RWC) were observed in response to water stress. Salinised M. lanceolata plants showed considerable osmotic adjustment and maintained Ψp comparable to that of control plants; salinity, however, decreased RWC. In response to the imposed stresses under laboratory conditions, proline and MHP levels in M. lanceolata, and MHP and DHP levels in M. uncinata, increased. In addition to possible protective or osmotic roles in vivo, these proline analogues may be useful in chemotaxonomic investigations of Melaleuca species.

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.

scholarly journals Expression of a novel DREB 5-A subgroup transcription factor gene from Ricinus communis (RcDREB1) enhanced growth, drought tolerance and pollen viability in tobacco

2021 ◽  
Author(s):  
Francisco Lima Aragão ◽  
Tomas Felipe Costa do Rego ◽  
Mirella Pupo Santos ◽  
Glaucia Barbosa Cabral ◽  
Thaís de Moura Cipriano ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Water Stress ◽  
Transgenic Plants ◽  
Drought Tolerance ◽  
Ricinus Communis ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Leaf Water ◽  
Economic Losses ◽  
Transgenic Lines

Abstract Climate change has increased the frequency of long periods of drought, affecting crop cultivation worldwide. Losses due to water stress exceed ten percent of world production of major crops, reaching three-quarters of production areas, with severe economic losses. Therefore, the generation of environmental stress-tolerant genotypes that are more efficient in water use is extremely important. We have previously isolated and characterized a DREB transcription factor coding gene, named RcDREB1, from castor bean (Ricinus communis L.), which probably belongs to the CBF/DREB subfamily subgroup A-5. Aiming to develop drought-tolerant lines, we have stably introduced and expressed the RcDREB1 transgene into tobacco. Transgenic lines have revealed an enhanced drought tolerance. Genetically modified lines cultivated under water deficit presented a higher photosynthetic rate, stomatal conductance, leaf water potential and leaf water content when compared to the control. Transgenic lines revealed lower transpiration rates. In addition, biometric analyses showed that transgenic lines cultivated under water stress presented higher biomass, higher fresh and dry weight and higher plant height than the non-transgenic lines. After re-watering, transgenic lines recovered faster than non-transgenic plants. Moreover, pollen grains from transgenic plants revealed a remarkable increase in viability after exposure to heat (38 ºC) and desiccation stresses. The results presented here will be the foundation for production of commercial crops that are more tolerant to environmental stresses and long-life pollen grains, increasing pollination and in consequence, productivity.

scholarly journals The MYB33, MYB65, and MYB101 transcription factors affect Arabidopsis and potato responses to drought by regulating the ABA signaling pathway

2021 ◽  
Author(s):  
Anna Wyrzykowska ◽  
Dawid Bielewicz ◽  
Patrycja Plewka ◽  
Dorota Sołtys-Kalina ◽  
Iwona Wasilewicz-Flis ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Transgenic Plants ◽  
Crop Production ◽  
Transgenic Arabidopsis ◽  
Water Shortage ◽  
Plant Response ◽  
High Tolerance ◽  
Potato Plants ◽  
Relative Water ◽  
Response To Water

AbstractAimsDrought is a climate threat limiting crop production. Potato is one of the four most important food crops worldwide and is sensitive to water shortage. The CBP80 gene was shown to affect plant response to drought by regulating the level of microRNA159, and, consequently, the levels of the MYB33 and MYB101 transcription factors. (TF) Our studies aimed to show whether indeed the level of MYB33, MYB65, and MYB101 TFs affects plant response to water shortage.MethodsArabidopsis transgenic plants exhibiting downregulation and Arabidopsis and potato transgenic plants exhibiting overexpression of selected MYB TFs were obtained. Plants response to drought was mainly measured using relative water content (RWC) and stomata closure upon exogenous ABA.ResultsThree MYB TFs studied are involved in plant response to drought. When downregulated in Arabidopsis, the MYB33, MYB65 and MYB101 genes cause stomatal hyposensitivity to ABA, leading to reduced tolerance to drought. Transgenic Arabidopsis and potato plants overexpressing a mutated version of these genes with changed miR159 recognition site, show hypersensitivity to ABA and relatively high tolerance to drought conditions.ConclusionsThe MYB33, MYB65, and MYB101 genes are good be potential targets for innovative breeding to obtain crops with relatively high tolerance to drought.

Primary Root Elongation Rate and Abscisic Acid Levels of Maize in Response to Water Stress

Crop Science ◽  
2011 ◽  
Vol 51 (1) ◽  
pp. 157-172 ◽  
Author(s):  
Kristen A. Leach ◽  
Lindsey G. Hejlek ◽  
Leonard B. Hearne ◽  
Henry T. Nguyen ◽  
Robert E. Sharp ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Water Stress ◽  
Root Elongation ◽  
Primary Root ◽  
Elongation Rate ◽  
Root Elongation Rate ◽  
Response To Water

scholarly journals Sex dimorphism in dioecious Palmer amaranth (Amaranthus palmeri) in response to water stress

Planta ◽  
2021 ◽  
Vol 254 (1) ◽  
Author(s):  
Mohsen B. Mesgaran ◽  
Maor Matzrafi ◽  
Sara Ohadi
Keyword(s):  
Water Stress ◽  
Weed Management ◽  
Amaranthus Palmeri ◽  
Ecological Management ◽  
State University ◽  
Dioecious Species ◽  
Seed Output ◽  
Flowering Asynchrony ◽  
Secondary Sex Characters ◽  
Response To Water

Abstract Main conclusion Phenological isolation can potentially reduce seed output and may be exploited as a novel tool for ecological management of dioecious weeds. Abstract Dioecious plants may benefit from a maximized outcrossing and optimal sex-specific resource allocation; however, this breeding system may also be exploited for weed management. Seed production in dioecious species is contingent upon the co-occurrence and co-flowering of the two genders and can be further disturbed by flowering asynchrony. We explored dimorphism in secondary sex characters in Amaranthus palmeri, and tested if reproductive synchrony can be affected by water stress. We have used seeds of A. palmeri from California, Kansas and Texas, and studied secondary sex characters under natural conditions and in response to water stress. Seeds of A. palmeri from California (CA) and Kansas (KS) were cordially provided by Dr. Anil Shrestha (California State University, Fresno, California) and Dr. Dallas E. Peterson (Kansas State University, Manhattan, Kansas), respectively. Seeds of a third population were collected from mature plants (about 30 plants) from a set-aside field in College Station, Texas. A. palmeri showed no sexual dimorphism with regard to the timing of emergence, plant height, and relative growth rate. While the initiation of flowering occurred earlier in males than females, females preceded males in timing of anthesis. Water stress delayed anthesis in males to a greater extent than females increasing the anthesis mismatch between the two sexes by seven days. Our data provide the first evidence of environment-controlled flowering asynchrony in A. palmeri. From a practical point of view, phenological isolation can potentially reduce seed output and may be exploited as a novel tool for ecological management of dioecious weeds.

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