Contribution of Plant Growth Regulators in Mitigation of Herbicidal Stress

Abstract

Weeds contribute to severe loss of agricultural crop productivity. Herbicides are efficient, cheap and effective method for their control, but their multiple uses at higher concentration have resulted in induced toxicity and stress in non-target crops. The herbicideinduced toxicity affects growth, photosynthesis, physiological and biochemical characteristics of plants directly impacting yield of plants. It is therefore, necessary to find ways to mitigate the herbicidal effects by increasing the tolerance of crops to their application. Plant growth regulators are known to promote growth and development of plants under optimal and stressful environment. They induce various physiological and biochemical responses and also confer tolerance of plants to abiotic stresses. The present review covers the aspects of herbicidal response of plants and evaluates the contribution of plant growth regulators in mitigating herbicidal stress effects and increasing the tolerance of plants. Further, future research in this direction to enhance our understanding on the relation between plant growth regulators and herbicides to improve tolerance of crop plants is discussed. The study suggests the use of plant growth regulators as a tool in mitigating effects of herbicidal stress together with improved growth and development. [29]. The decrease in photosynthetic characteristics with herbicides might have involved its effects on chlorophyll biosynthetic pathway and enzymes of carbon assimilation. The details on the key points in the biosynthetic pathway of photosynthetic pigments and activity of carbon assimilation enzymes are still lacking and needs attention. Chlorophyll fluorescence is a simple and widely used method to study the mechanism of photosynthesis and is used as marker to detect stress in plants. The herbicides application may block photosynthesis related intermediate metabolites and affect fluorescence emission. The herbicides that inhibit glutamine synthase, protoporphyrinogen oxidase and carotenoid biosynthesis affect chlorophyll fluorescence [30], and even lipid synthesis inhibitor herbicides induce chlorophyll fluorescence. Application of 1.96 kg ha -1 Terbutryn to Vicia faba plants strongly decreased F v /F m ratio and CO 2 assimilation capacity [31]. Recently, Sousa et al. [32] have shown that application of imidazolinone group of herbicides to Oryza sativa changed the photosynthetic metabolism of plants and chlorophyll a fluorescence. Contribution of Plant Growth Regulators in Mitigation of Herbicidal Stress OsmolytesThe production of osmolytes is an adaptation against stress in plants [33]. These osmolytes include polyols (sugars, fructans, mannitol, pinitol and inositol), amino acids and their derivatives (proline, isoleucine, valine, betaine, glycinebetaine). Proline is widely studied osmolyte that acts as a cellular protector in several plant species by scavenging ROS produced in response to abiotic stress [34][35][36]. It provides resistance against stress either by uniting oxygen and free radicals g...

Salicylic Acid Pretreatment Modulates Wheat Responses to Glyphosate

“…However, usage of non-selective herbicides also induces stressful circumstances and causes injury to the non-target plants. Plants treated with herbicides undergo an increased generation of reactive oxygen species-ROS [40,41]. Over-accumulation of ROS triggers chain oxidation reactions that cause adverse effects on plant metabolism, leading to retarded crop growth and reduced yield and quality of agricultural production.…”

“…Generally, measurement of the quantity of stress biomarkers gives valuable assessment for induced stress damages. To survive the destructive consequences of the unfavorable environmental factors, plants have evolved an effective ROS-scavenging defense system which includes enzymatic and non-enzymatic antioxidants that assist plants to continued growth under harsh environment and contribute to stress tolerance [1,2,40]. The antioxidant machinery includes enzymatic (SOD, CAT, POX APX, glutathione peroxidase, GR, MDHAR, DHAR and GST) and non-enzymatic antioxidant systems (ascorbic acid, glutathione, tocopherol, etc.)…”

“…that work coordinately to regulate ROS [42]. The protective capacity of plants could be increased due to application of different plant growth regulating substances, including SA [40]. In this connection, the objective of our study was to assess the potential of SA to mitigate glyphosate-induced stress injuries in wheat through measurement of basic cellular and biochemical traits that participate in the antioxidant network.…”

The Effect of Increasing Doses of Foliar Applied Regulators of Polyamine Biosynthesis in Mixture With Triazine Herbicide on Formation of Spring Barley Biomass

“…Polyamines (putrescine, spermidine and spermine) are also known to participate in plants for protection against abiotic stress conditions (Groppa and Benavides, 2007). Spermidine offered protection against paraquat toxicity in Raphanus sativus seedlings (Varshney et al, 2015;Kim and Jin, 2006). Diethylenetriamine polyamine increased the protection against 2, 4-D herbicide in the triticale plants.…”

Physiological and biochemical responses of selected weed and crop species to the plant-based bioherbicide WeedLock

“…ROS has been reported to be involved in abiotic and biotic stress signaling and response by influencing the expression of several genes and in turn affecting several processes like cell division, elongation, systemic signaling, and development 18 . Plant growth hormone maintains photosynthetic activity, antioxidant enzyme activation, and osmoprotectants accumulation in response to oxidative stress via inducing expression of stress-related genes 19,20 . Plant growth regulators including ethylene, salicylic acid, abscisic acid and jasmonic acid are known to promote growth and development of plants under optimal conditions.…”