scholarly journals Biological Roles of Ornithine Aminotransferase (OAT) in Plant Stress Tolerance: Present Progress and Future Perspectives

2018 ◽  
Vol 19 (11) ◽  
pp. 3681 ◽  
Author(s):  
Alia Anwar ◽  
Maoyun She ◽  
Ke Wang ◽  
Bisma Riaz ◽  
Xingguo Ye

Plant tolerance to biotic and abiotic stresses is complicated by interactions between different stresses. Maintaining crop yield under abiotic stresses is the most daunting challenge for breeding resilient crop varieties. In response to environmental stresses, plants produce several metabolites, such as proline (Pro), polyamines (PAs), asparagine, serine, carbohydrates including glucose and fructose, and pools of antioxidant reactive oxygen species. Among these metabolites, Pro has long been known to accumulate in cells and to be closely related to drought, salt, and pathogen resistance. Pyrroline-5-carboxylate (P5C) is a common intermediate of Pro synthesis and metabolism that is produced by ornithine aminotransferase (OAT), an enzyme that functions in an alternative Pro metabolic pathway in the mitochondria under stress conditions. OAT is highly conserved and, to date, has been found in all prokaryotic and eukaryotic organisms. In addition, ornithine (Orn) and arginine (Arg) are both precursors of PAs, which confer plant resistance to drought and salt stresses. OAT is localized in the cytosol in prokaryotes and fungi, while OAT is localized in the mitochondria in higher plants. We have comprehensively reviewed the research on Orn, Arg, and Pro metabolism in plants, as all these compounds allow plants to tolerate different kinds of stresses.

2010 ◽  
Vol 8 (3) ◽  
pp. 3-15
Author(s):  
Olga A Kulaeva ◽  
Viktor E Tsyganov

 Cadmium (Cd) is one of the most wide-ranged and dangerous pollutants for all living organisms, including plants. At present time the intensive studies of mechanisms of Cd accumulation in plant tissues and plant tolerance to its toxic influence are performed. Data about variation of Cd tolerance and accumulation traits in natural populations of hyperaccumulators species as well as important crops were obtained. A series of mutants with changed sensitivity to Cd was obtained. In recent decade several classes of proteins involving in cell responses to Cd ions were revealed. An important role of microRNA in plant adaptation to Cd was recently demonstrated. Studies of molecular-genetic mechanisms of Cd accumulation and plant tolerance to it are theoretical basis for development of phytoremediation technologies of soil contaminated with heavy metals and breeding of crop varieties with decreased Cd accumulation.


2021 ◽  
Vol 22 (3) ◽  
pp. 1088
Author(s):  
Weitao Jia ◽  
Maohua Ma ◽  
Jilong Chen ◽  
Shengjun Wu

Globally, flooding is a major threat causing substantial yield decline of cereal crops, and is expected to be even more serious in many parts of the world due to climatic anomaly in the future. Understanding the mechanisms of plants coping with unanticipated flooding will be crucial for developing new flooding-tolerance crop varieties. Here we describe survival strategies of plants adaptation to flooding stress at the morphological, physiological and anatomical scale systemically, such as the formation of adventitious roots (ARs), aerenchyma and radial O2 loss (ROL) barriers. Then molecular mechanisms underlying the adaptive strategies are summarized, and more than thirty identified functional genes or proteins associated with flooding-tolerance are searched out and expounded. Moreover, we elaborated the regulatory roles of phytohormones in plant against flooding stress, especially ethylene and its relevant transcription factors from the group VII Ethylene Response Factor (ERF-VII) family. ERF-VIIs of main crops and several reported ERF-VIIs involving plant tolerance to flooding stress were collected and analyzed according to sequence similarity, which can provide references for screening flooding-tolerant genes more precisely. Finally, the potential research directions in the future were summarized and discussed. Through this review, we aim to provide references for the studies of plant acclimation to flooding stress and breeding new flooding-resistant crops in the future.


2022 ◽  
Vol 23 (2) ◽  
pp. 702
Author(s):  
Shuya Tan ◽  
Jie Cao ◽  
Xinli Xia ◽  
Zhonghai Li

Priming is an adaptive strategy that improves plant defenses against biotic and abiotic stresses. Stimuli from chemicals, abiotic cues, and pathogens can trigger the establishment of priming state. Priming with 5-aminolevulinic acid (ALA), a potential plant growth regulator, can enhance plant tolerance to the subsequent abiotic stresses, including salinity, drought, heat, cold, and UV-B. However, the molecular mechanisms underlying the remarkable effects of ALA priming on plant physiology remain to be elucidated. Here, we summarize recent progress made in the stress tolerance conferred by ALA priming in plants and provide the underlying molecular and physiology mechanisms of this phenomenon. Priming with ALA results in changes at the physiological, transcriptional, metabolic, and epigenetic levels, and enhances photosynthesis and antioxidant capacity, as well as nitrogen assimilation, which in turn increases the resistance of abiotic stresses. However, the signaling pathway of ALA, including receptors as well as key components, is currently unknown, which hinders the deeper understanding of the defense priming caused by ALA. In the future, there is an urgent need to reveal the molecular mechanisms by which ALA regulates plant development and enhances plant defense with the help of forward genetics, multi-omics technologies, as well as genome editing technology.


2021 ◽  
Author(s):  
Venera S. Kamburova ◽  
Ilkhom B. Salakhutdinov ◽  
Shukhrat E. Shermatov ◽  
Ibrokhim Y. Abdurakhmonov

The main task of plant breeding is creating of high-yield, resistant to biotic and abiotic stresses crop varieties with high product quality. The using of traditional breeding methods is limited by the duration of the new crop varieties creation with the required agronomic traits. This depends not only on the duration of growing season and reaching of mature stage of plants (especially the long-period growth plants, e.g. trees), as well as is associated with applying of multiple stages of crossing, selection and testing in breeding process. In addition, conventional methods of chemical and physical mutagenesis do not allow targeting effect to genome. However, the introduction of modern DNA-technology methods, such as genome editing, has opened in a new era in plant breeding. These methods allow to carry out precise and efficient targeted genome modifications, significantly reducing the time required to get plants with desirable features to create new crop varieties in perspective. This review provides the knowledge about application of genome editing methods to increase crop yields and product quality, as well as crop resistance to biotic and abiotic stresses. In addition, future prospects for integrating these technologies into crop breeding strategies are also discussed.


2019 ◽  
Vol 22 (8) ◽  
pp. 987-991 ◽  
Author(s):  
E. A. Trifonova ◽  
S. M. Ibragimova ◽  
O. A. Volkova ◽  
V. K. Shumny ◽  
A. V. Kochetov

Disease resistance is an important characteristic for each variety of potato, and the search for pathogen resistance markers is one of the primary tasks of plant breeding. Higher plants possess a wide spectrum of enzymes catalyzing the hydrolysis of nucleic acids; it is believed that protection against pathogens is the most probable function of the enzymes. RNases are actively involved in several immune systems of higher plants, for example, systemic acquired resistance (SAR) and genetic silencing, hence RNase activity in plant leaves, as a relatively easily measured parameter, can serve as a good marker for the selection of pathogen resistant varieties. We have analyzed sixteen varieties of potatoes permitted for use on the territory of the Russian Federation and tested the correlation of the level of variety­specifc ribonuclease (RNase) activity with such economically valuable traits as maturity and resistance to viruses, late blight and common scab. In general, the level of RNase activity was variety­specifc, which was confrmed by very small values of average squared error for the majority of tested varieties. We have detected a statistically signifcant positive correlation of RNase activity in potato leaves with increased resistance of varieties to phytopathogenic viruses, a negative correlation with resistance to scab and an absence of a signifcant connection with maturity and resistance to late blight, regardless of the organ affected by the oomycete. Thus, the level of RNase activity in potato leaves can be used as a selective marker for resistance to viruses, while varieties with increased RNase activity should be avoided when selecting resistance to scab.


2021 ◽  
Author(s):  
liang xu ◽  
Jia-Qian Song ◽  
yuelin wang ◽  
Xiao-Han Liu ◽  
Xue-Li Li ◽  
...  

Abstract Plants have evolved a lot of strategies to improve salt tolerance to cope with salt stress. Recent studies have suggested that thymol (a nature medicine) enhances the plant tolerance against abiotic stresses, but the mechanisms are rarely known. Here, we found that thymol played an important role in maintaining root growth under salt stress. Thymol rescued root growth from salt stress via ameliorating ROS (reactive oxygen species) accumulation, lipid peroxidation, and cell death. In addition, thymol enhanced the level of NO (nitric oxide) and GSH (glutathione) to repress ROS accumulation, further protecting the stability of cell membrane. Thymol-induced Na+ efflux in roots and leaves under salt stress may depend on the upregulation of SOS1, HKT1 and NHX1. Consequently, all of these evidences suggested that thymol improved tobacco salt tolerance via enhancing NO and GSH content as well as inducing Na+ efflux.


2020 ◽  
Vol 71 (21) ◽  
pp. 6758-6774 ◽  
Author(s):  
Mohammad Abass Ahanger ◽  
Javaid Akhter Bhat ◽  
Manzer H Siddiqui ◽  
Jörg Rinklebe ◽  
Parvaiz Ahmad

Abstract As sessile organisms, plants are unable to avoid being subjected to environmental stresses that negatively affect their growth and productivity. Instead, they utilize various mechanisms at the morphological, physiological, and biochemical levels to alleviate the deleterious effects of such stresses. Amongst these, secondary metabolites produced by plants represent an important component of the defense system. Secondary metabolites, namely phenolics, terpenes, and nitrogen-containing compounds, have been extensively demonstrated to protect plants against multiple stresses, both biotic (herbivores and pathogenic microorganisms) and abiotic (e.g. drought, salinity, and heavy metals). The regulation of secondary metabolism by beneficial elements such as silicon (Si) is an important topic. Silicon-mediated alleviation of both biotic and abiotic stresses has been well documented in numerous plant species. Recently, many studies have demonstrated the involvement of Si in strengthening stress tolerance through the modulation of secondary metabolism. In this review, we discuss Si-mediated regulation of the synthesis, metabolism, and modification of secondary metabolites that lead to enhanced stress tolerance, with a focus on physiological, biochemical, and molecular aspects. Whilst mechanisms involved in Si-mediated regulation of pathogen resistance via secondary metabolism have been established in plants, they are largely unknown in the case of abiotic stresses, thus leaving an important gap in our current knowledge.


2007 ◽  
Vol 147 (2) ◽  
pp. 422-428 ◽  
Author(s):  
Yongchao Liang ◽  
Wanchun Sun ◽  
Yong-Guan Zhu ◽  
Peter Christie

Diversity ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 407
Author(s):  
Xiang Yu ◽  
Yan Bao

Genetic studies on model plants and crops in the last few decades have uncovered numerous genes that play vital roles in plant tolerance to adverse environments. These genes could be used as targets for genetic engineering to improve plant tolerance to abiotic and biotic stresses. Recent advances in CRISPR-based genome editing have accelerated modern plant breeding and wild-species domestication. However, the stress regulators in many crops and horticultural cultivars and their wild species remain largely unexplored. Thus, transferring the accumulated knowledge of these molecular regulators from model plants to a wider range of other species is critical for modern plant breeding. Phylogenetic analysis is one of the powerful strategies for studying the functional conservation and diversity of homologous gene families among different species with complete genome sequences available. In addition, many transcriptome datasets of plants under stress conditions have been publicly released, providing a useful resource for addressing the stress response of given gene families. This Special Issue aims to illustrate the phylogenetics of molecular regulators with potential in contributing to plant stress tolerance and their stress response diversity in multiple non-model plants.


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