Proline, a multifaceted signalling molecule in plant responses to abiotic stress: understanding the physiological mechanisms

Plants are constantly challenged by changing environmental conditions that include abiotic stresses. These are limiting their development and productivity and are subsequently threatening our food security, especially when considering the pressure of the increasing global population. Thus, there is an urgent need for the next generation of crops with high productivity and resilience to climate change. The dawn of a new era characterized by the emergence of fourth industrial revolution (4IR) technologies has redefined the ideological boundaries of research and applications in plant sciences. Recent technological advances and machine learning (ML)-based computational tools and omics data analysis approaches are allowing scientists to derive comprehensive metabolic descriptions and models for the target plant species under specific conditions. Such accurate metabolic descriptions are imperatively essential for devising a roadmap for the next generation of crops that are resilient to environmental deterioration. By synthesizing the recent literature and collating data on metabolomics studies on plant responses to abiotic stresses, in the context of the 4IR era, we point out the opportunities and challenges offered by omics science, analytical intelligence, computational tools and big data analytics. Specifically, we highlight technological advancements in (plant) metabolomics workflows and the use of machine learning and computational tools to decipher the dynamics in the chemical space that define plant responses to abiotic stress conditions.

Download Full-text

Ozone responses in Arabidopsis: beyond stomatal conductance

Plant Physiology ◽

10.1093/plphys/kiab097 ◽

2021 ◽

Author(s):

Luis O Morales ◽

Alexey Shapiguzov ◽

Omid Safronov ◽

Johanna Leppälä ◽

Lauri Vaahtera ◽

...

Keyword(s):

Cell Death ◽

Tropospheric Ozone ◽

Natural Variation ◽

Air Pollutant ◽

Plant Responses ◽

Negative Effects ◽

Transcriptional Responses ◽

Physiological Mechanisms ◽

Future Studies ◽

Key Parameter

Abstract Tropospheric ozone (O3) is a major air pollutant that decreases yield of important crops worldwide. Despite long-lasting research of its negative effects on plants, there are many gaps in our knowledge on how plants respond to O3. In this study, we used natural variation in the model plant Arabidopsis (Arabidopsis thaliana) to characterize molecular and physiological mechanisms underlying O3 sensitivity. A key parameter in models for O3 damage is stomatal uptake. Here we show that the extent of O3 damage in the sensitive Arabidopsis accession Shahdara (Sha) does not correspond with O3 uptake, pointing toward stomata-independent mechanisms for the development of O3 damage. We compared tolerant (Col-0) versus sensitive accessions (Sha, Cvi-0) in assays related to photosynthesis, cell death, antioxidants, and transcriptional regulation. Acute O3 exposure increased cell death, development of lesions in the leaves, and decreased photosynthesis in sensitive accessions. In both Sha and Cvi-0, O3-induced lesions were associated with decreased maximal chlorophyll fluorescence and low quantum yield of electron transfer from Photosystem II to plastoquinone. However, O3-induced repression of photosynthesis in these two O3-sensitive accessions developed in different ways. We demonstrate that O3 sensitivity in Arabidopsis is influenced by genetic diversity given that Sha and Cvi-0 developed accession-specific transcriptional responses to O3. Our findings advance the understanding of plant responses to O3 and set a framework for future studies to characterize molecular and physiological mechanisms allowing plants to respond to high O3 levels in the atmosphere as a result of high air pollution and climate change.

Download Full-text

Potassium: A Vital Regulator of Plant Responses and Tolerance to Abiotic Stresses

Agronomy ◽

10.3390/agronomy8030031 ◽

2018 ◽

Vol 8 (3) ◽

pp. 31 ◽

Cited By ~ 73

Author(s):

Mirza Hasanuzzaman ◽

M. Bhuyan ◽

Kamrun Nahar ◽

Md. Hossain ◽

Jubayer Mahmud ◽

...

Keyword(s):

Abiotic Stress ◽

Stress Tolerance ◽

Molecular Mechanisms ◽

Abiotic Stress Tolerance ◽

Ion Homeostasis ◽

Enzyme Activation ◽

Regulatory Function ◽

Plant Responses ◽

Plant Structure ◽

Physiological Processes

Among the plant nutrients, potassium (K) is one of the vital elements required for plant growth and physiology. Potassium is not only a constituent of the plant structure but it also has a regulatory function in several biochemical processes related to protein synthesis, carbohydrate metabolism, and enzyme activation. Several physiological processes depend on K, such as stomatal regulation and photosynthesis. In recent decades, K was found to provide abiotic stress tolerance. Under salt stress, K helps to maintain ion homeostasis and to regulate the osmotic balance. Under drought stress conditions, K regulates stomatal opening and helps plants adapt to water deficits. Many reports support the notion that K enhances antioxidant defense in plants and therefore protects them from oxidative stress under various environmental adversities. In addition, this element provides some cellular signaling alone or in association with other signaling molecules and phytohormones. Although considerable progress has been made in understanding K-induced abiotic stress tolerance in plants, the exact molecular mechanisms of these protections are still under investigation. In this review, we summarized the recent literature on the biological functions of K, its uptake, its translocation, and its role in plant abiotic stress tolerance.

Download Full-text

Seed priming with non-ionizing physical agents: plant responses and underlying physiological mechanisms

Plant Cell Reports ◽

10.1007/s00299-021-02798-y ◽

2021 ◽

Author(s):

Kuntal Bera ◽

Puspendu Dutta ◽

Sanjoy Sadhukhan

Keyword(s):

Seed Priming ◽

Plant Responses ◽

Physiological Mechanisms

Download Full-text

High temperatures modify plant responses to abiotic stress conditions

Physiologia Plantarum ◽

10.1111/ppl.13151 ◽

2020 ◽

Vol 170 (3) ◽

pp. 335-344 ◽

Cited By ~ 3

Author(s):

Damián Balfagón ◽

Sara I. Zandalinas ◽

Ron Mittler ◽

Aurelio Gómez‐Cadenas

Keyword(s):

Abiotic Stress ◽

High Temperatures ◽

Stress Conditions ◽

Plant Responses

Download Full-text

Regulatory role of circadian clocks in plant responses to abiotic stress

Plant Life Under Changing Environment ◽

10.1016/b978-0-12-818204-8.00036-9 ◽

2020 ◽

pp. 811-823

Author(s):

Mohamed A. El-Esawi ◽

Ibrahim M. Abdelsalam

Keyword(s):

Abiotic Stress ◽

Circadian Clocks ◽

Regulatory Role ◽

Plant Responses

Download Full-text

Advances in Omics Approaches for Abiotic Stress Tolerance in Tomato

Biology ◽

10.3390/biology8040090 ◽

2019 ◽

Vol 8 (4) ◽

pp. 90 ◽

Cited By ~ 7

Author(s):

Juhi Chaudhary ◽

Praveen Khatri ◽

Pankaj Singla ◽

Surbhi Kumawat ◽

Anu Kumari ◽

...

Keyword(s):

Abiotic Stress ◽

Stress Tolerance ◽

Association Studies ◽

Abiotic Stress Tolerance ◽

Crop Improvement ◽

Genetic Regulatory Networks ◽

Plant Responses ◽

Genome Wide Association Studies ◽

Market Demand ◽

Efficient Utilization

Tomato, one of the most important crops worldwide, has a high demand in the fresh fruit market and processed food industries. Despite having considerably high productivity, continuous supply as per the market demand is hard to achieve, mostly because of periodic losses occurring due to biotic as well as abiotic stresses. Although tomato is a temperate crop, it is grown in almost all the climatic zones because of widespread demand, which makes it challenge to adapt in diverse conditions. Development of tomato cultivars with enhanced abiotic stress tolerance is one of the most sustainable approaches for its successful production. In this regard, efforts are being made to understand the stress tolerance mechanism, gene discovery, and interaction of genetic and environmental factors. Several omics approaches, tools, and resources have already been developed for tomato growing. Modern sequencing technologies have greatly accelerated genomics and transcriptomics studies in tomato. These advancements facilitate Quantitative trait loci (QTL) mapping, genome-wide association studies (GWAS), and genomic selection (GS). However, limited efforts have been made in other omics branches like proteomics, metabolomics, and ionomics. Extensive cataloging of omics resources made here has highlighted the need for integration of omics approaches for efficient utilization of resources and a better understanding of the molecular mechanism. The information provided here will be helpful to understand the plant responses and the genetic regulatory networks involved in abiotic stress tolerance and efficient utilization of omics resources for tomato crop improvement.

Download Full-text

Identification of conserved and novel miRNAs responsive to heat stress in flowering Chinese cabbage using high-throughput sequencing

Scientific Reports ◽

10.1038/s41598-019-51443-y ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Waqas Ahmed ◽

Yanshi Xia ◽

Hua Zhang ◽

Ronghua Li ◽

Guihua Bai ◽

...

Keyword(s):

Heat Stress ◽

Abiotic Stress ◽

High Throughput ◽

Chinese Cabbage ◽

Stress Responses ◽

High Throughput Sequencing ◽

Differential Expression Analysis ◽

Plant Responses ◽

Limited Information ◽

Flowering Chinese Cabbage

Abstract Plant microRNAs (miRNAs) are noncoding and endogenous key regulators that play significant functions in regulating plant responses to stress, and plant growth and development. Heat stress is a critical abiotic stress that reduces the yield and quality of flowering Chinese cabbage (Brassica campestris L. ssp. chinensis var. utilis Tsen et Lee). However, limited information is available on whether miRNAs are involved in the regulation of heat stress in B. campestris. A high-throughput sequencing approach was used to identify novel and conserved heat-responsive miRNAs in four small RNA libraries of flowering Chinese cabbage using leaves collected at 0 h, 1 h, 6 h and 12 h after a 38 °C heat-stress treatment. The analysis identified 41 conserved miRNAs (belonging to 19 MIR families), of which MIR156, MIR159, MIR168, MIR171 and MIR1885 had the most abundant molecules. Prediction and evaluation of novel miRNAs using the unannotated reads resulted in 18 candidate miRNAs. Differential expression analysis showed that most of the identified miRNAs were downregulated in heat-treated groups. To better understand functional importance, bioinformatic analysis predicted 432 unique putative target miRNAs involved in cells, cell parts, catalytic activity, cellular processes and abiotic stress responses. Furthermore, the Kyoto Encyclopedia of Genes and Genomes maps of flowering Chinese cabbage identified the significant role of miRNAs in stress adaptation and stress tolerance, and in several mitogen-activated protein kinases signaling pathways including cell death. This work presents a comprehensive study of the miRNAs for understanding the regulatory mechanisms and their participation in the heat stress of flowering Chinese cabbage.

Download Full-text