Arabidopsis DREB26/ERF12 and its close relatives regulate cuticular wax biosynthesis under drought stress condition.

Land plants have evolved a hydrophobic cuticle on the surface of aerial organs as an adaptation to ensure survival in terrestrial environments. Cuticle is mainly composed of lipids, namely cutin and intracuticular wax, with epicuticular wax deposited on plant surface. The composition and permeability of cuticle have a large influence on its ability to protect plants against drought stress.

Division Zone Activity Determines the Potential of Drought-Stressed Maize Leaves to Resume Growth after Rehydration.

Drought is one of the most devastating causes of yield losses in crops like maize, and the anticipated increases in severity and duration of drought spells due to climate change pose an imminent threat to agricultural productivity. To understand the drought response, phenotypic and molecular studies are typically performed at a given time point after drought onset, representing a steady-state adaptation response. Because growth is a dynamic process, we monitored the drought response with high temporal resolution and examined cellular and transcriptomic changes after rehydration at 4 and 6 days after leaf four appearance.

A Case Study from the Overexpression of OsTZF5, Encoding a CCCH Tandem Zinc Finger Protein, in Rice Plants Across Nineteen Yield Trials.

Background: Development of transgenic rice overexpressing transcription factors involved in drought response has been previously reported to confer drought tolerance and therefore represents a means of crop improvement. We transformed lowland rice IR64 with OsTZF5, encoding a CCCH-tandem zinc finger protein, under the control of the rice LIP9 stress-inducible promoter and compared the drought response of transgenic lines and nulls to IR64 in successive screenhouse paddy and field trials up to the T generation.

Results: Compared to the well-watered conditions, the level of drought stress across experiments varied from a minimum of - 25 to - 75 kPa at a soil depth of 30 cm which reduced biomass by 30-55% and grain yield by 1-92%, presenting a range of drought severities.

Regulatory networks in plant responses to drought and cold stress.

Drought and cold represent distinct types of abiotic stress, each initiating unique primary signaling pathways in response to dehydration and temperature changes, respectively. However, a convergence at the gene regulatory level is observed where a common set of stress-responsive genes is activated to mitigate the impacts of both stresses. In this review, we explore these intricate regulatory networks, illustrating how plants coordinate distinct stress signals into a collective transcriptional strategy.

Complex plant responses to drought and heat stress under climate change.

Global climate change is predicted to result in increased yield losses of agricultural crops caused by environmental conditions. In particular, heat and drought stress are major factors that negatively affect plant development and reproduction, and previous studies have revealed how these stresses induce plant responses at physiological and molecular levels. Here, we provide a comprehensive overview of current knowledge concerning how drought, heat, and combinations of these stress conditions affect the status of plants, including crops, by affecting factors such as stomatal conductance, photosynthetic activity, cellular oxidative conditions, metabolomic profiles, and molecular signaling mechanisms.

Constitutively active B2 Raf-like kinases are required for drought-responsive gene expression upstream of ABA-activated SnRK2 kinases.

Osmotic stresses, such as drought and high salinity, adversely affect plant growth and productivity. The phytohormone abscisic acid (ABA) accumulates in response to osmotic stress and enhances stress tolerance in plants by triggering multiple physiological responses through ABA signaling. Subclass III SNF1-related protein kinases 2 (SnRK2s) are key regulators of ABA signaling.

Clock-regulated coactivators selectively control gene expression in response to different temperature stress conditions in .

Plants respond to severe temperature changes by inducing the expression of numerous genes whose products enhance stress tolerance and responses. Dehydration-responsive element (DRE)-binding protein 1/C-repeat binding factor (DREB1/CBF) transcription factors act as master switches in cold-inducible gene expression. Since genes are rapidly and strongly induced by cold stress, the elucidation of the molecular mechanisms of expression is vital for the recognition of the initial responses to cold stress in plants.

OsTZF1, a CCCH-tandem zinc finger protein gene, driven under own promoter produces no pleiotropic effects and confers salt and drought tolerance in rice.

Different abiotic stresses induce , a tandem CCCH-type zinc finger domain gene, in rice. Here, we report that transgenic rice plants overexpressing under own promoter (OX [for overexpression]) transferred to soil showed normal growth similar to vector control plants. The OX produced normal leaves without any lesion mimic phenotype and exhibited normal seed setting.

Functional genomics in plant abiotic stress responses and tolerance: From gene discovery to complex regulatory networks and their application in breeding.

Land plants have developed sophisticated systems to cope with severe stressful environmental conditions during evolution. Plants have complex molecular systems to respond and adapt to abiotic stress, including drought, cold, and heat stress. Since 1989, we have been working to understand the complex molecular mechanisms of plant responses to severe environmental stress conditions based on functional genomics approaches with Arabidopsis thaliana as a model plant.

Transcriptional regulatory network of plant cold-stress responses.

Recent studies have revealed the complex and flexible transcriptional regulatory network involved in cold-stress responses. Focusing on two major signaling pathways that respond to cold stress, we outline current knowledge of the transcriptional regulatory network and the post-translational regulation of transcription factors in the network. Cold-stress signaling pathways are closely associated with other signaling pathways such as those related to the circadian clock, and large amounts of data on their crosstalk and tradeoffs are available.

Affinity Purification Followed by Liquid Chromatography-Tandem Mass Spectrometry to Identify Proteins Interacting with ABA Signaling Components.

Abscisic acid (ABA) is a key phytohormone involved in plant development, seed germination and responses to osmotic stresses, such as drought and high salinity. SNF1-related protein kinases (SnRK2s) play important roles in ABA-dependent and ABA-independent osmotic stress signaling. SnRK2s phosphorylate transcription factors and ion channels in response to ABA or osmotic stress to induce the expression of stress-responsive genes and stomatal closure, respectively, to confer osmotic stress tolerance.

TBP-ASSOCIATED FACTOR 12 ortholog NOBIRO6 controls root elongation with unfolded protein response cofactor activity.

Plant root growth is indeterminate but continuously responds to environmental changes. We previously reported on the severe root growth defect of a double mutant in and () modulating the unfolded protein response (UPR). To elucidate the mechanism by which seedlings develop a short root, we obtained a series of suppressor mutants, called , for rescued root growth.

CIN-like TCP13 is essential for plant growth regulation under dehydration stress.

A dehydration-inducible Arabidopsis CIN-like TCP gene, TCP13, acts as a key regulator of plant growth in leaves and roots under dehydration stress conditions. Plants modulate their shape and growth in response to environmental stress. However, regulatory mechanisms underlying the changes in shape and growth under environmental stress remain elusive.

Inter-tissue and inter-organ signaling in drought stress response and phenotyping of drought tolerance.

Plant response to drought stress includes systems for intracellular regulation of gene expression and signaling, as well as inter-tissue and inter-organ signaling, which helps entire plants acquire stress resistance. Plants sense water-deficit conditions both via the stomata of leaves and roots, and transfer water-deficit signals from roots to shoots via inter-organ signaling. Abscisic acid is an important phytohormone involved in the drought stress response and adaptation, and is synthesized mainly in vascular tissues and guard cells of leaves.

Corrigendum: Drought Stress Responses and Resistance in Plants: From Cellular Responses to Long-Distance Intercellular Communication.

[This corrects the article DOI: 10.3389/fpls.2020.

Cellular Phosphorylation Signaling and Gene Expression in Drought Stress Responses: ABA-Dependent and ABA-Independent Regulatory Systems.

Drought is a severe and complex abiotic stress that negatively affects plant growth and crop yields. Numerous genes with various functions are induced in response to drought stress to acquire drought stress tolerance. The phytohormone abscisic acid (ABA) accumulates mainly in the leaves in response to drought stress and then activates subclass III SNF1-related protein kinases 2 (SnRK2s), which are key phosphoregulators of ABA signaling.

Posttranslational regulation of multiple clock-related transcription factors triggers cold-inducible gene expression in .

Cold stress is an adverse environmental condition that affects plant growth, development, and crop productivity. Under cold stress conditions, the expression of numerous genes that function in the stress response and tolerance is induced in various plant species, and the dehydration-responsive element (DRE) binding protein 1/C-repeat binding factor (DREB1/CBF) transcription factors function as master switches for cold-inducible gene expression. Cold stress strongly induces these genes.

Metabolic engineering: Towards water deficiency adapted crop plants.

Water deficiency caused by drought is one of the severe environmental conditions limiting plant growth, development, and yield. In this review article, we will summarize the changes in transcription, metabolism, and phytohormones under drought stress conditions and show the key transcription factors in these processes. We will also highlight the recent attempts to enhance stress tolerance without growth retardation and discuss the perspective on the development of stress adapted crops by engineering transcription factors.

Cytosolic HSC70s repress heat stress tolerance and enhance seed germination under salt stress conditions.

Heat shock factor A1 (HsfA1) family proteins are the master regulators of the heat stress-responsive transcriptional cascade in Arabidopsis. Although 70 kDa heat shock proteins (HSP70s) are known to participate in repressing HsfA1 activity, the mechanisms by which they regulate HsfA1 activity have not been clarified. Here, we report the physiological functions of three cytosolic HSP70s, HSC70-1, HSC70-2 and HSC70-3, under normal and stress conditions.

Constitutive expression of Arabidopsis bZIP transcription factor AREB1 activates cross-signaling responses in soybean under drought and flooding stresses.

Abiotic stress, such as drought and flooding, are responsible for considerable losses in grain production worldwide. Soybean, the main cultivated oilseed in the world, is sensitive to both stresses. Plant molecular mechanisms answer via crosstalk of several signaling pathways, in which particular genes can respond to different stresses.

Drought Stress Responses and Resistance in Plants: From Cellular Responses to Long-Distance Intercellular Communication.

The drought stress responses of vascular plants are complex regulatory mechanisms because they include various physiological responses from signal perception under water deficit conditions to the acquisition of drought stress resistance at the whole-plant level. It is thought that plants first recognize water deficit conditions in roots and that several molecular signals then move from roots to shoots. Finally, a phytohormone, abscisic acid (ABA) is synthesized mainly in leaves.

DNA demethylase ROS1 prevents inheritable DREB1A/CBF3 repression by transgene-induced promoter methylation in the Arabidopsis ice1-1 mutant.

In the ros1-defective mutant, DREB1A repression by the transgene-induced promoter methylation of ice1-1 became inheritable across generations even in the absence of the causative transgene NICE1. Transgene silencing (TGS) is a widely observed event during plant bioengineering, which is presented as a gradual decrease in ectopic gene expression across generations and occasionally coupled with endogenous gene silencing based on DNA sequence similarity. TGS is known to be established by guided DNA methylation machinery.