Role of Abscisic Acid in the Management of Drought (Research Paper Sample)

Role of Abscisic Acid in the Management of Drought
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Outline
This paper is going to be structured as follows;
* Introduction –here the definition of abscisic acid, its source and where it's found will be expounded. Additionally the issue of drought will be brought into perspective.
* Body .the body is going to be fragmented in five sections each discussing a summary of the details of each of the article in the order they are listed below.
* Genetic and Molecular Aspects of Plant Response to Drought in Annual Crop Species
* An ABA-mimicking ligand that reduces water loss and promotes drought resistance in plants
* Abscisic Acid Mediates a Divergence in the Drought Response of Two Coifers.
* Abscisic acid improves drought tolerance of triploidbermudagrass and involves H2O2- and NO-induced antioxidant enzyme activities.
* "Activation of dimeric ABA receptors elicits guard cell closure, ABA-regulated gene expression, and drought tolerance.”
* Conclusion: this will give a general overview on the role of abscisic acid in the management of water stress. The discussion will draw its conclusions from the paper listed above.
Role of Abscisic Acid in the Management of Drought
Abscisic acid also referred to as (ABA) is a plant hormone and lone compound that appears naturally. It is chemically presented using the symbols C 15 H 20 O 4 .The name Abscisic acid was coined as it was believed to be the compound behind abscission of fruits. Another clutch of scientists based their naming on their belief that dormancy of the bud was caused by the hormone thus they referred to it as Dormin. ABA is a fifteen carbon compound that is partly manufactured through the mevalonic conduit in chloroplasts as well as in other plastids (Seo and Koshiba, 2011). It's also important to note that it aids the process of biosynthesis taking place in the leaves indirectly through the making of carotenoids from the chloroplasts.
The carotenoids usually have forty carbons and it's usually isomerized before it's subsequently subjected to an isomerase and oxidation reaction respectively. The product of these reactions is xanthonin though little is known about what remains without being used in the reaction process. Extra addition of oxygen in the process results in the production of ABA as the xanthonin molecule is unstable. The rate of production of abscisic acid is significantly influenced by fluctuations on volumes of water available to the plant or sharp decline of temperatures towards the freezing point. Its movement in the plants is through the paranchyma cells, phloem or the xylem tissues. Unlike auxins, the movement of ABA is not accompanied by polarization. The study on the role of ABA is occasioned by the fact that it is critical to management of water stress in plants.
Environmental changes that have been witnessed in the recent past globally, have greatly affected the climate. Plant life as well as animal life has thus suffered a big blow as they must devise new strategies to cope with these conditions or else they become extinct. Despite formulating new strategies to cope with these climatic changes, they are inhibited in their growing and consequently their genetic potential yields by the unpredictable weather conditions. Such effects especially on agrarian crops that are beneficial to humanity, pose a great threat to productivity and consequently the food security of the affected area. Owing to the potential capability ABA has to intervene in such desperate situations of stress such as that of drought, cold among other factors that affect the growth of plants, it's important to explore the specific role abscisic acid plays in saving the plants from total dead of plants while under such drought stress. Plants respond to drought according to their genotype and species (Pinheiro and Chaves, 2011).This paper is going to critically explore the role of abscisic   acid in reduction the water loss and promotes drought resistance. It will draw its conclusion from a summation of five papers that have been written about abscisic acid.
Genetic and Molecular Aspects of Plant Response to Drought in Annual Crop Species
This paper explored comprehensively, the reaction of plants whenever they are faced with environmental stress. When plants are faced with water stress, they embark on physiological-, biochemical- and molecular-based mechanisms to enhance their survival chances during the drought period (Chaves, Pereira, Maroco, Rodrigues, Ricardo, Osòrio, Carvalho, Faria and & Pinheiro, 2002). It is also important to mention that molecular variations as well as morpho-physiological attributes are critical in the process of stress management in plants. The engineering of drought tolerant plants can successfully take place following an insightful analysis of characteristics of areas involved in stress management as well as the molecular mechanisms to the same. The engineering of drought tolerant crops is such an important thing in crop propagation as water loss affects both the amount of water available to a plant as well as the yield quality (Pinheiro and Chaves, 2011). This is possible if the chief phenotypic characteristics of a plant to cope with drought are established.
-946154148826Drought Resistance strategiesEscape Avoidance Tolerance Accelerating the life cycle Preventing exposure to stress Permitting the plant to withstand stressEarly flowering and/or short minimizing water loss maximizing water uptake osmoregulationGrowth duration increased root proliferation osmotic adjustment Closing the stomata stomata regulation Leaf rolling deeper tap root ABA ROS scavenging Leaf glauclousness Scenesence of older leaves Reduced leaf area00Drought Resistance strategiesEscape Avoidance Tolerance Accelerating the life cycle Preventing exposure to stress Permitting the plant to withstand stressEarly flowering and/or short minimizing water loss maximizing water uptake osmoregulationGrowth duration increased root proliferation osmotic adjustment Closing the stomata stomata regulation Leaf rolling deeper tap root ABA ROS scavenging Leaf glauclousness Scenesence of older leaves Reduced leaf area2751162415956700Biological attributes of plants related to water inadequacy responses or alterations they adopt are all important in the process. Among the morphological features that help a plant cope with water stress may be prompt plant vigour, enlarged leaves and swift soil cover to inhibit water loss though evaporation and competition of water with other plants. Knowledge of a plant's phenology helps configure the plants life span in tandem with the target drought period. This basically means that the process of engineering drought tolerant plants must take into account expected season of the drought. Despite this observation, higher yields may be enjoyed if the drought comes during the early season at the initial vegetative stage. In addition early flowering crops may be able to avoid terminal drought but cannot be termed as drought tolerant. Plants that do not enjoy this may cope with drought by closing their stomata to lower loss of water as well as gaseous exchange which in turn leads to decrease in the process of photosynthesis
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Fig. 1. Plant drought response mechanisms and main related traits
(Hedrich, 2013).
All the same for high quality yield to be realized there is need for high stomatal conductance so as to sustain great CO2 fixation. The high yielding modern wheat for instance has opportunistic capabilities as it has high stomatal conductance when there are high water levels in the soil and reduce the same when there is water stress. Osmotic regulations through
osmotic adjustment is an adaptive mechanism in which the accretion of solutes helps retain favorable water potential gradient of the plant, soil and air. This attribute enables plant yield more has none of its basic processes such as photosynthesis and transpiration are hampered. Having deep roots also enable plant access water from a wide range area in the soil hence as such they are able to manage water stress.
A Lot has been achieved in terms of engineering drought resistant crops especially cereals and legumes globally through the analysis of the genotype interaction with the environment. High yield crops adapted to well-balanced environments can also perform well in scarce resource environments.
Plant response to water stress is also is also influenced by Molecular and biochemical activities of the plant. The synthesis of lipids and membrane sensitivity are fundamentally responsible for detecting abiotic stress. Another contemporary mechanism in response to drought is Epigenetic regulation. Crops that have Transgenic Arabidopsis and overexpressing AtHD2C show improved manifestation of ABA-responsive genes and more drought ...