Overexpression of BvHb2, a Class 2 Non-Symbiotic Hemoglobin from Sugar Beet, Confers Drought-Induced Withering Resistance and Alters Iron Content in Tomato

Drought stress is one of the major threats to agriculture and concomitantly to food production. Tomato is one of the most important industrial crops, but its tolerance to water scarcity is very low. Traditional plant breeding has a limited margin to minimize this water requirement. In order to design novel biotechnological approaches to cope with this problem, we have screened a plant cDNA library from the halotolerant crop sugar beet (Beta vulgaris L.) for genes able to confer drought/osmotic stress tolerance to the yeast model system upon overexpression. We have identified the gene that encodes BvHb2, a class 2 non-symbiotic hemoglobin, which is present as a single copy in the sugar beet genome, expressed mainly in leaves and regulated by light and abiotic stress. We have evaluated its biotechnological potential in the model plant Arabidopsis thaliana and found that BvHb2 is able to confer drought and osmotic stress tolerance. We also generated transgenic lines of tomato (Solanum lycopersicum) overexpressing BvHb2 and found that the resulting plants are more resistant to drought-induce withering. In addition, transgenic lines overexpressing BvHb2 exhibit increased levels of iron content in leaves. Here, we show that class 2 non-symbiotic plant hemoglobins are targets to generate novel biotechnological crops tolerant to abiotic stress. The fact that these proteins are conserved in plants opens the possibility for using Non-GMO approaches, such as classical breeding, molecular breeding, or novel breeding techniques to increase drought tolerance using this protein as a target.

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The NAC Protein from Tamarix hispida, ThNAC7, Confers Salt and Osmotic Stress Tolerance by Increasing Reactive Oxygen Species Scavenging Capability

Plants ◽

10.3390/plants8070221 ◽

2019 ◽

Vol 8 (7) ◽

pp. 221 ◽

Cited By ~ 2

Author(s):

Zihang He ◽

Ziyi Li ◽

Huijun Lu ◽

Lin Huo ◽

Zhibo Wang ◽

...

Keyword(s):

Reactive Oxygen Species ◽

Abiotic Stress ◽

Osmotic Stress ◽

Stress Tolerance ◽

Oxygen Species ◽

Tamarix Hispida ◽

Ros Scavenging ◽

Transcription Level ◽

Osmotic Stress Tolerance ◽

Salt And Osmotic Stress

Plant specific NAC (NAM, ATAF1/2 and CUC2) transcription factors (TFs) play important roles in response to abiotic stress. In this study, we identified and characterized a NAC protein, ThNAC7, from Tamarix hispida. ThNAC7 is a nuclear localized protein and has transcriptional activation activity. ThNAC7 expression was markedly induced by salt and osmotic stresses. Transiently transformed T. hispida seedlings overexpressing ThNAC7 (OE) or with RNA interference (RNAi) silenced ThNAC7 were generated to investigate abiotic stress tolerance via the gain- and loss- of function. Overexpressing ThNAC7 showed an increased reactive oxygen species (ROS) scavenging capabilities and proline content, which was accomplished by enhancing the activities of superoxide dismutase (SOD) and peroxidase (POD) in transiently transformed T. hispida and stably transformed Arabidopsis plants. Additionally, ThNAC7 activated these physiological changes by regulating the transcription level of P5CS, SOD and POD genes. RNA-sequencing (RNA-seq) comparison between wild-type and ThNAC7-transformed Arabidopsis showed that more than 40 known salt tolerance genes might regulated by ThNAC7, including stress tolerance-related genes and TF genes. The results indicated that ThNAC7 induces the transcription level of genes associated with stress tolerance to enhance salt and osmotic stress tolerance via an increase in osmotic potential and enhanced ROS scavenging.

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Faculty Opinions recommendation of The plant cuticle is required for osmotic stress regulation of abscisic acid biosynthesis and osmotic stress tolerance in Arabidopsis.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.11003957.11944056 ◽

2011 ◽

Author(s):

Tapio Palva

Keyword(s):

Abscisic Acid ◽

Osmotic Stress ◽

Stress Tolerance ◽

Plant Cuticle ◽

Acid Biosynthesis ◽

Abscisic Acid Biosynthesis ◽

Stress Regulation ◽

Osmotic Stress Tolerance

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CAND2/PMTR1 Is Required for Melatonin-Conferred Osmotic Stress Tolerance in Arabidopsis

International Journal of Molecular Sciences ◽

10.3390/ijms22084014 ◽

2021 ◽

Vol 22 (8) ◽

pp. 4014

Author(s):

Lin-Feng Wang ◽

Ting-Ting Li ◽

Yu Zhang ◽

Jia-Xing Guo ◽

Kai-Kai Lu ◽

...

Keyword(s):

Osmotic Stress ◽

Stress Tolerance ◽

Wild Type Plant ◽

Wild Type ◽

Melatonin Receptor ◽

Ros Scavenging ◽

Exogenous Melatonin ◽

Osmotic Stress Tolerance ◽

Osmotic Stress Response ◽

In The Wild

Osmotic stress severely inhibits plant growth and development, causing huge loss of crop quality and quantity worldwide. Melatonin is an important signaling molecule that generally confers plant increased tolerance to various environmental stresses, however, whether and how melatonin participates in plant osmotic stress response remain elusive. Here, we report that melatonin enhances plant osmotic stress tolerance through increasing ROS-scavenging ability, and melatonin receptor CAND2 plays a key role in melatonin-mediated plant response to osmotic stress. Upon osmotic stress treatment, the expression of melatonin biosynthetic genes including SNAT1, COMT1, and ASMT1 and the accumulation of melatonin are increased in the wild-type plants. The snat1 mutant is defective in osmotic stress-induced melatonin accumulation and thus sensitive to osmotic stress, while exogenous melatonin enhances the tolerance of the wild-type plant and rescues the sensitivity of the snat1 mutant to osmotic stress by upregulating the expression and activity of catalase and superoxide dismutase to repress H2O2 accumulation. Further study showed that the melatonin receptor mutant cand2 exhibits reduced osmotic stress tolerance with increased ROS accumulation, but exogenous melatonin cannot revert its osmotic stress phenotype. Together, our study reveals that CADN2 functions necessarily in melatonin-conferred osmotic stress tolerance by activating ROS-scavenging ability in Arabidopsis.

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Precursor processing by SBT3.8 and phytosulfokine signaling contribute to drought stress tolerance in Arabidopsis

Journal of Experimental Botany ◽

10.1093/jxb/erab017 ◽

2021 ◽

Author(s):

Nils Stührwohldt ◽

Eric Bühler ◽

Margret Sauter ◽

Andreas Schaller

Keyword(s):

Drought Stress ◽

Osmotic Stress ◽

Stress Tolerance ◽

Serine Proteases ◽

Loss Of Function ◽

Lateral Root Development ◽

Osmotic Stress Tolerance ◽

Stress Symptoms ◽

C Terminus ◽

Peptide Precursor

Abstract Increasing drought stress poses a severe threat to agricultural productivity. Plants, however, evolved numerous mechanisms to cope with such environmental stress. Here we report that the stress-induced production of a peptide signal contributes to stress tolerance. The expression of phytosulfokine (PSK) peptide precursor genes, and transcripts of three subtilisin-like serine proteases, SBT1.4, SBT3.7 and SBT3.8 were found to be up-regulated in response to osmotic stress. Stress symptoms were enhanced in sbt3.8 loss-of-function mutants and could be alleviated by PSK treatment. Osmotic stress tolerance was improved in plants overexpressing the precursor of PSK1 (proPSK1) or SBT3.8 resulting in higher fresh weight and improved lateral root development in the transgenic compared to wild-type plants. We further showed that SBT3.8 is involved in the biogenesis of the bioactive PSK peptide. ProPSK1 was cleaved by SBT3.8 at the C-terminus of the PSK pentapeptide. Processing by SBT3.8 depended on the aspartic acid residue directly following the cleavage site. ProPSK1 processing was impaired in the sbt3.8 mutant. The data suggest that increased expression in response to osmotic stress followed by the post-translational processing of proPSK1 by SBT3.8 leads to the production of PSK as a peptide signal for stress mitigation.

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