Relationship between gibberellins, height, and stress tolerance in barley (Hordeum vulgare L.) seedlings

Sarkar, Sunita; Perras, Michel; Falk, D. E.; Zhang, Ruichuan; Pharis, Richard P.; Fletcher, R. A.

doi:10.1023/b:grow.0000017492.56792.64

Cited by 31 publications

(14 citation statements)

References 104 publications

(245 reference statements)

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“…The total chlorophyll content which includes chlorophyll a and b nearly doubled in plants treated with PBZ only compared to untreated. Similar results were obtained in PBZ treated barley seedlings (Sunitha et al, 2004) and tomato (Still and Pill, 2003) whereby chlorophyll content was two-fold higher than untreated.…”

Section: Discussionsupporting

confidence: 83%

Distribution of Silicified Microstructures, Regulation of Cinnamyl Alcohol Dehydrogenase and Lodging Resistance in Silicon and Paclobutrazol Mediated Oryza sativa

Dorairaj

Ismail

2017

Front. Physiol.

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Lodging is a phenomenon that affects most of the cereal crops including rice, Oryza sativa. This is due to the fragile nature of herbaceous plants whose stems are non-woody, thus affecting its ability to grow upright. Silicon (Si), a beneficial nutrient is often used to toughen and protect plants from biotic and abiotic stresses. Deposition of Si in plant tissues enhances the rigidity and stiffness of the plant as a whole. Silicified cells provide the much needed strength to the culm to resist breaking. Lignin plays important roles in cell wall structural integrity, stem strength, transport, mechanical support, and plant pathogen defense. The aim of this study is to resolve effects of Si on formation of microstructure and regulation of cinnamyl alcohol dehydrogenase (CAD), a key gene responsible for lignin biosynthesis. Besides evaluating silicon, paclobutrazol (PBZ) a plant growth retartdant that reduces internode elongation is also incorporated in this study. Hardness, brittleness and stiffness were improved in presence of silicon thus reducing lodging. Scanning electron micrographs with the aid of energy dispersive x-ray (EDX) was used to map silicon distribution. Presence of trichomes, silica cells, and silica bodies were detected in silicon treated plants. Transcripts of CAD gene was also upregulated in these plants. Besides, phloroglucinol staining showed presence of lignified vascular bundles and sclerenchyma band. In conclusion, silicon treated rice plants showed an increase in lignin content, silicon content, and formation of silicified microstructures.

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Section: Discussionsupporting

confidence: 83%

Distribution of Silicified Microstructures, Regulation of Cinnamyl Alcohol Dehydrogenase and Lodging Resistance in Silicon and Paclobutrazol Mediated Oryza sativa

Dorairaj

Ismail

2017

Front. Physiol.

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“…It has been reported that GA functions in diametrically opposed capacities in response to abiotic stresses. GA is involved in stress tolerance during germination and seedling establishment (Kabar and Baltepe, 1990;Kaur et al, 1998;Nasri et al, 2011), whereas it is involved in stress intolerance in established vegetative tissues (Sarkar et al, 2004;Achard et al, 2006). In the tissues of Arabidopsis, DELLA/RGA-LIKE3 is induced by the transcriptional activator AtCBF1/DREB1B in response to cold and water deprivation (Achard et al, 2008).…”

Section: Discussionmentioning

confidence: 99%

“…A quadruple DELLA mutant lacking Gibberellic Acid Insensitive (GAI), Repressor of GA (RGA), RGA-Like1 (RGL1), and RGL2 is more sensitive to salt stress than the wild-type plant. In barley (Hordeum vulgare) seedlings, treatment with GA inhibitors leads to higher tolerance to heat and oxidative stresses (Sarkar et al, 2004). Barley seedlings, which have the largest concentrations of endogenous GAs, are most susceptible to these abiotic stresses.…”

mentioning

confidence: 99%

Reduction of Gibberellin by Low Temperature Disrupts Pollen Development in Rice

et al. 2014

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Microsporogenesis in rice (Oryza sativa) plants is susceptible to moderate low temperature (LT; approximately 19°C) that disrupts pollen development and causes severe reductions in grain yields. Although considerable research has been invested in the study of cool-temperature injury, a full understanding of the molecular mechanism has not been achieved. Here, we show that endogenous levels of the bioactive gibberellins (GAs) GA 4 and GA 7 , and expression levels of the GA biosynthesis genes GA20ox3 and GA3ox1, decrease in the developing anthers by exposure to LT. By contrast, the levels of precursor GA 12 were higher in response to LT. In addition, the expression of the dehydration-responsive element-binding protein DREB2B and SLENDER RICE1 (SLR1)/DELLA was up-regulated in response to LT. Mutants involved in GA biosynthetic and response pathways were hypersensitive to LT stress, including the semidwarf mutants sd1 and d35, the gain-of-function mutant slr1-d, and gibberellin insensitive dwarf1. The reduction in the number of sporogenous cells and the abnormal enlargement of tapetal cells occurred most severely in the GA-insensitive mutant. Application of exogenous GA significantly reversed the male sterility caused by LT, and simultaneous application of exogenous GA with sucrose substantially improved the extent of normal pollen development. Modern rice varieties carrying the sd1 mutation are widely cultivated, and the sd1 mutation is considered one of the greatest achievements of the Green Revolution. The protective strategy achieved by our work may help sustain steady yields of rice under global climate change.

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“…In contrast, plants overexpressing GA2ox which is responsible for catabolism of growth-active GA 1 and GA 4 to their catabolite forms, GA 8 and GA 34 respectively, and catabolism of precursors to growth-active GAs, GA 20 and GA 9 to their catabolite forms, GA 29 and GA 51 , respectively (Figure 1), exhibit a dwarf phenotype relative to wild-type (WT) plants [48,54,55]. It is well established that a change in temperature modifies endogenous GA levels [56–58], as well as the plant’s sensitivity to the application of exogenous growth-active GAs [59]. Endogenous GA levels decrease as temperature is lowered and this is associated with decreased shoot growth in carrot ( Daucus carota L.) [60], wheat ( Triticum aestivum L.) [61], Campanula isophylla [62], Dendranthema grandiflorum [63] and sunflower ( Helianthus annuus L.) [58].…”

Section: Cbf–hormone Interactions Cold Acclimation and Dwarf Phenmentioning

confidence: 99%

Role of CBFs as Integrators of Chloroplast Redox, Phytochrome and Plant Hormone Signaling during Cold Acclimation

Kurepin

Dahal

Savitch

et al. 2013

IJMS

132

100

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Cold acclimation of winter cereals and other winter hardy species is a prerequisite to increase subsequent freezing tolerance. Low temperatures upregulate the expression of C-repeat/dehydration-responsive element binding transcription factors (CBF/DREB1) which in turn induce the expression of COLD-REGULATED (COR) genes. We summarize evidence which indicates that the integration of these interactions is responsible for the dwarf phenotype and enhanced photosynthetic performance associated with cold-acclimated and CBF-overexpressing plants. Plants overexpressing CBFs but grown at warm temperatures mimic the cold-tolerant, dwarf, compact phenotype; increased photosynthetic performance; and biomass accumulation typically associated with cold-acclimated plants. In this review, we propose a model whereby the cold acclimation signal is perceived by plants through an integration of low temperature and changes in light intensity, as well as changes in light quality. Such integration leads to the activation of the CBF-regulon and subsequent upregulation of COR gene and GA 2-oxidase (GA2ox) expression which results in a dwarf phenotype coupled with increased freezing tolerance and enhanced photosynthetic performance. We conclude that, due to their photoautotrophic nature, plants do not rely on a single low temperature sensor, but integrate changes in light intensity, light quality, and membrane viscosity in order to establish the cold-acclimated state. CBFs appear to act as master regulators of these interconnecting sensing/signaling pathways.

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Relationship between gibberellins, height, and stress tolerance in barley (Hordeum vulgare L.) seedlings

Cited by 31 publications

References 104 publications

Distribution of Silicified Microstructures, Regulation of Cinnamyl Alcohol Dehydrogenase and Lodging Resistance in Silicon and Paclobutrazol Mediated Oryza sativa

Distribution of Silicified Microstructures, Regulation of Cinnamyl Alcohol Dehydrogenase and Lodging Resistance in Silicon and Paclobutrazol Mediated Oryza sativa

Reduction of Gibberellin by Low Temperature Disrupts Pollen Development in Rice

Role of CBFs as Integrators of Chloroplast Redox, Phytochrome and Plant Hormone Signaling during Cold Acclimation

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