Statistical method for testing the neutral mutation hypothesis by DNA polymorphism.

Abiotic Stress Signaling and Responses in Plants

Abiotic stress is a primary threat to fulfill the demand of agricultural production to feed the world in coming decades. Plants reduce growth and development process during stress conditions, which ultimately affect the yield. In stress conditions, plants develop various stress mechanism to face the magnitude of stress challenges, although that is not enough to protect them. Therefore, many strategies have been used to produce abiotic stress tolerance crop plants, among them, ABA (abscisic acid) phytohormone engineering could be one of the methods of choice. ABA is an isoprenoid phytohormone, which regulates various physiological processes ranging from stomatal opening to protein storage and provides adaptation to many stresses like drought, salt, and cold stresses. ABA is also called an important messenger that acts as the signaling mediator for regulating the adaptive response of plants to different environmental stress conditions. In this review, we will discuss the role of ABA in response to abiotic stress at the molecular level and ABA signaling. The review also deals with the effect of ABA in respect to gene expression.

/pdf/abscisic-acid-and-abiotic-stress-tolerance-in-crop-plants-20w770vsmh.pdf

Abscisic Acid and Abiotic Stress Tolerance in Crop Plants

Contents Summary 523 I. Introduction 523 II. Sensing salt stress 524 III. Ion homeostasis regulation 524 IV. Metabolite and cell activity responses to salt stress 527 V. Conclusions and perspectives 532 Acknowledgements 533 References 533 SUMMARY: Excess soluble salts in soil (saline soils) are harmful to most plants. Salt imposes osmotic, ionic, and secondary stresses on plants. Over the past two decades, many determinants of salt tolerance and their regulatory mechanisms have been identified and characterized using molecular genetics and genomics approaches. This review describes recent progress in deciphering the mechanisms controlling ion homeostasis, cell activity responses, and epigenetic regulation in plants under salt stress. Finally, we highlight research areas that require further research to reveal new determinants of salt tolerance in plants.

https://nph.onlinelibrary.wiley.com/doi/epdf/10.1111/nph.14920

Elucidating the molecular mechanisms mediating plant salt-stress responses

The plasma membrane

Abiotic stresses and soil nutrient limitations are major environmental conditions that reduce plant growth, productivity and quality. Plants have evolved mechanisms to perceive these environmental challenges, transmit the stress signals within cells as well as between cells and tissues, and make appropriate adjustments in their growth and development in order to survive and reproduce. In recent years, significant progress has been made on many fronts of the stress signaling research, particularly in understanding the downstream signaling events that culminate at the activation of stress- and nutrient limitation-responsive genes, cellular ion homeostasis, and growth adjustment. However, the revelation of the early events of stress signaling, particularly the identification of primary stress sensors, still lags behind. In this review, we summarize recent work on the genetic and molecular mechanisms of plant abiotic stress and nutrient limitation sensing and signaling and discuss new directions for future studies.

Plant abiotic stress response and nutrient use efficiency.

OST1 Kinase Modulates Freezing Tolerance by Enhancing ICE1 Stability in Arabidopsis

Contents Summary I. Introduction II. Cold stress and physiological responses in plants III. Sensing of cold signals in plants IV. Messenger molecules involved in cold signal transduction V. Cold signal transduction in plants VI. Conclusions and perspectives Acknowledgements References SUMMARY: Cold stress is a major environmental factor that seriously affects plant growth and development, and influences crop productivity. Plants have evolved a series of mechanisms that allow them to adapt to cold stress at both the physiological and molecular levels. Over the past two decades, much progress has been made in identifying crucial components involved in cold-stress tolerance and dissecting their regulatory mechanisms. In this review, we summarize recent major advances in our understanding of cold signalling and put forward open questions in the field of plant cold-stress responses. Answering these questions should help elucidate the molecular mechanisms underlying plant tolerance to cold stress.

https://nph.onlinelibrary.wiley.com/doi/pdf/10.1111/nph.15696

Advances and challenges in uncovering cold tolerance regulatory mechanisms in plants.

https://www.cell.com/trends/plant-science/pdf/S1360-1385(18)30086-4.pdf

Molecular Regulation of CBF Signaling in Cold Acclimation.

Summary
In Arabidopsis, the C-repeat binding factors (CBFs) have been extensively studied as key transcription factors in the cold stress response. However, their exact functions in the cold response remains unclear due to the lack of a null cbf triple mutant.
In this study, we used CRISPR/Cas9 technology to mutate CBF1 or CBF1/CBF2 in a cbf3 T-DNA insertion mutant to generate cbf1,3 double and cbf1 cbf2 cbf3 (cbfs) triple mutants.
The response of the cbfs triple mutants to chilling stress is impaired. Furthermore, no significant difference in freezing tolerance was observed between the wild-type and the cbf1,3 and cbfs mutants without cold acclimation. However, the cbfs mutants were extremely sensitive to freezing stress after cold acclimation, and freezing sensitivity ranking was cbfs > cbf1,3 > cbf3. RNA-Seq analysis showed that 134 genes were CBF regulated, of which 112 were regulated positively and 22 negatively by CBFs.
Our study reveals the essential functions of CBFs in chilling stress response and cold acclimation, as well as defines a set of genes as CBF regulon. It also provides materials for the genetic dissection of components in CBF-dependent cold signaling.

Yanglin Ding

Papers

Plant abiotic stress response and nutrient use efficiency.

OST1 Kinase Modulates Freezing Tolerance by Enhancing ICE1 Stability in Arabidopsis

Advances and challenges in uncovering cold tolerance regulatory mechanisms in plants.

Molecular Regulation of CBF Signaling in Cold Acclimation.

The cbfs triple mutants reveal the essential functions of CBFs in cold acclimation and allow the definition of CBF regulons in Arabidopsis.