Improving Performance of Salt-Grown Crops by Exogenous Application of Plant Growth Regulators

Soil salinity is one of the major abiotic stresses restricting plant growth and development. Application of plant growth regulators (PGRs) is a possible practical means for minimizing salinity-induced yield losses, and can be used in addition to or as an alternative to crop breeding for enhancing salinity tolerance. The PGRs auxin, cytokinin, nitric oxide, brassinosteroid, gibberellin, salicylic acid, abscisic acid, jasmonate, and ethylene have been advocated for practical use to improve crop performance and yield under saline conditions. This review summarizes the current knowledge of the effectiveness of various PGRs in ameliorating the detrimental effects of salinity on plant growth and development, and elucidates the physiological and genetic mechanisms underlying this process by linking PGRs with their downstream targets and signal transduction pathways. It is shown that, while each of these PGRs possesses an ability to alter plant ionic and redox homeostasis, the complexity of interactions between various PGRs and their involvement in numerous signaling pathways makes it difficult to establish an unequivocal causal link between PGRs and their downstream effectors mediating plants’ adaptation to salinity. The beneficial effects of PGRs are also strongly dependent on genotype, the timing of application, and the concentration used. The action spectrum of PGRs is also strongly dependent on salinity levels. Taken together, this results in a rather narrow “window” in which the beneficial effects of PGR are observed, hence limiting their practical application (especially under field conditions). It is concluded that, in the light of the above complexity, and also in the context of the cost–benefit analysis, crop breeding for salinity tolerance remains a more reliable avenue for minimizing the impact of salinity on plant growth and yield. Further progress in the field requires more studies on the underlying cell-based mechanisms of interaction between PGRs and membrane transporters mediating plant ion homeostasis.

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VERSATILE ROLE OF AUXIN AND ITS CROSSTALK WITH OTHER PLANT HORMONES TO REGULATE PLANT GROWTH AND DEVELOPMENT

PLANT ARCHIVES ◽

10.51470/plantarchives.2021.v21.no1.221 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Hammad Ishtiaq ◽

Savita Bhardwaj ◽

Aaliya Ashraf ◽

Dhriti Kapoor

Keyword(s):

Cell Cycle ◽

Plant Growth ◽

Plant Growth Regulators ◽

Growth Regulators ◽

Plant Hormones ◽

Growth And Development ◽

Naphthalene Acetic Acid ◽

Plant Growth And Development ◽

Indole Butyric Acid ◽

Cellular Processes

Plant growth regulators are significant chemical compounds which are synthesized inside the plant cells and play vital role in plant growth and development. Such compounds are usually active at very low concentrations. These plant growth regulators act as a signalling molecule, which influences the growth of plants. Throughout the previous year’s remarkable investigation have been done for understanding the synthesis of auxin and its effect on various physiological progressions. Auxin is a plant hormone that is involved in various physiological activities, including basic cellular processes such as cell enlargement, regulation of the cell cycle and distinction progress. Plants and several other microorganisms together produce auxin in order to carry out their cell cycle. The chemically synthesized auxins like NAA (naphthalene acetic acid) and IBA (Indole- butyric acid), also take part in various cellular processes. Against various types of biotic and abiotic stress conditions, these plant hormones significantly contribute in promoting acclimatization and adaptation in combination with other phytohormones. The present review highlights some of the important features of auxin role in regulation of plant growth either alone or in crosstalk with other plant hormones.

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Amelioration of Salinity Tolerance in Foxtail Millet by Applying Plant Growth Regulators

Bangladesh Agronomy Journal ◽

10.3329/baj.v22i2.47618 ◽

2020 ◽

Vol 22 (2) ◽

pp. 25-39

Author(s):

D Biswas ◽

MA Mannan ◽

MA Karim ◽

MY Miah

Keyword(s):

Humic Acid ◽

Plant Growth ◽

Plant Growth Regulators ◽

Salinity Tolerance ◽

Growth Regulators ◽

Foxtail Millet ◽

Growth And Yield ◽

Spad Value ◽

Randomized Design ◽

Salinity Levels

A pot experiment was laid down at the Department of Agronomy, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur from November 2018 to March 2019 to improving the salinity tolerance in Foxtail millet (BARI Kaon 1) using different plant growth regulators with different doses. Two salinity levels, i) control (0mM NaCl) and ii) 80 mMNaCl were maintained after 14 days of sowing to harvest. The plant growth regulators i) Humic acid (HA): a) @ 5 gL-1 water b) @ 10 gL−1water ii) Gibberellic acid (GA3): a) @10 g L-1water b) @20 g L-1water iii) Salicylic acid (SA): a) @ 50 g L-1water b) @ 100 g L-1water were sprayed at 7 days interval from salt imposition. The experiment was in a completely randomized design (CRD) with three replications. Results revealed that plant growth regulators improved the growth and yield performance of Foxtail millet under both control and saline conditions. Amelioration of salinity tolerance in Foxtail millet was well associated with lower proline content, higher chlorophyll content and SPAD value as well as dry matter production, which facilitated the Foxtail millet yield due to application of plant growth regulators. Among the plant growth regulators, humic acid (HA) @ 5 g L-1 water was the best treatment to improving the salinity tolerance in foxtail millet under saline condition. Bangladesh Agron. J. 2019, 22(2): 25-39

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Plant growth regulators promote growth and yield of summer tomato (lycopersicone sculentum Mill.)

Progressive Agriculture ◽

10.3329/pa.v26i1.24512 ◽

2015 ◽

Vol 26 (1) ◽

pp. 32-37 ◽

Cited By ~ 3

Author(s):

M Rahman ◽

MA Nahar ◽

MS Sahariar ◽

MR Karim

Keyword(s):

Plant Growth ◽

Plant Height ◽

Plant Growth Regulators ◽

Growth Regulators ◽

Growth Regulator ◽

Plant Growth Regulator ◽

Fruit Weight ◽

Fruit Yield ◽

Growth And Yield ◽

The Impact

An experiment was conducted at the Horticulture Farm of Bangladesh Agricultural University, Mymensingh to test the impact of plant growth regulators on growth and yield of summer tomato. The experiment consisted of two tomato varieties viz. BARI Hybrid Tomato-4 and BARI Hybrid Tomato-8 and four types of plant growth regulator (PGR)viz.,(i) control (without PGR), (ii) 4-CPA (4-chlorophenoxy acetic acid), GA3 (gibberellic acid) and 4-CPA +GA3. The two-factor experiment was laid out in randomized complete block design with three replications. The results of the experiment revealed that significant variations were observed for most of the characters studied. At 75 DAT, the tallest plant (79.35 cm), number of flowers and fruits (38.11 and 19.04, respectively) plant-1, individual weight (58.44 g) and fruit yield (22.75 t ha-1) were found in BARI Hybrid Tomato-8.At 75 DAT the maximum plant height (87.90 cm), number of flowers and fruits (49.04 and 21.9, respectively) plant-1, individual fruit weight (61.16 g), and fruit yield (27.28 tha-1) were found when 4-CPA + GA3 applied together, whereas the minimum for these characters were recorded from control plants. In case of combined effect of variety and plant growth regulator, the maximum plant height (87.90 cm), number of flowers and fruits (49.04 and 21.91, respectively) plant-1, individual fruit weight (61.16 g) and fruit yield (27.28 t ha-1) were observed in BARI Hybrid Tomato-8 when treated with 4-CPA + GA3together, and the minimum for all these parameters were found in control plants. The results of the present study suggest thatboth 4-CAP and GA3together can be practiced for increasing summer tomato production for both the varieties.Progressive Agriculture 26:32-37, 2015

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Potential Role of Plant Growth Regulators in Administering Crucial Processes Against Abiotic Stresses

Frontiers in Agronomy ◽

10.3389/fagro.2021.648694 ◽

2021 ◽

Vol 3 ◽

Author(s):

Ayman EL Sabagh ◽

Sonia Mbarki ◽

Akbar Hossain ◽

Muhammad Aamir Iqbal ◽

Mohammad Sohidul Islam ◽

...

Keyword(s):

Plant Growth ◽

Plant Growth Regulators ◽

Growth Regulators ◽

Stress Responses ◽

Abiotic Stresses ◽

Growth And Development ◽

Stress Proteins ◽

Growth And Yield ◽

Physiological Processes ◽

Current Review

Plant growth regulators are naturally biosynthesized chemicals in plants that influence physiological processes. Their synthetic analogous trigger numerous biochemical and physiological processes involved in the growth and development of plants. Nowadays, due to changing climatic scenario, numerous biotic and abiotic stresses hamper seed germination, seedling growth, and plant development leading to a decline in biological and economic yields. However, plant growth regulators (PGRs) can potentially play a fundamental role in regulating plant responses to various abiotic stresses and hence, contribute to plant adaptation under adverse environments. The major effects of abiotic stresses are growth and yield disturbance, and both these effects are directly overseen by the PGRs. Different types of PGRs such as abscisic acid (ABA), salicylic acid (SA), ethylene (ET), and jasmonates (JAs) are connected to boosting the response of plants to multiple stresses. In contrast, PGRs including cytokinins (CKs), gibberellins (GAs), auxin, and relatively novel PGRs such as strigolactones (SLs), and brassinosteroids (BRs) are involved in plant growth and development under normal and stressful environmental conditions. Besides, polyamines and nitric oxide (NO), although not considered as phytohormones, have been included in the current review due to their involvement in the regulation of several plant processes and stress responses. These PGRs are crucial for regulating stress adaptation through the modulates physiological, biochemical, and molecular processes and activation of the defense system, upregulating of transcript levels, transcription factors, metabolism genes, and stress proteins at cellular levels. The current review presents an acumen of the recent progress made on different PGRs to improve plant tolerance to abiotic stress such as heat, drought, salinity, and flood. Moreover, it highlights the research gaps on underlying mechanisms of PGRs biosynthesis under stressed conditions and their potential roles in imparting tolerance against adverse effects of suboptimal growth conditions.

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INFLUENCE OF SPRAYING BY SOME PLANT GROWTH REGULATORS ON DATE PALM SALT TOLERANCE ENHANCEMENT

IRAQI JOURNAL OF AGRICULTURAL SCIENCES ◽

10.36103/ijas.v48i1.439 ◽

2017 ◽

Vol 48 (1) ◽

Author(s):

Al-Sahaf & et al.

Keyword(s):

Plant Growth ◽

Plant Growth Regulators ◽

Growth Regulators ◽

Date Palm ◽

Phoenix Dactylifera ◽

Growth And Yield ◽

Naphthalene Acetic Acid ◽

Trunk Diameter ◽

Significant Difference ◽

The Impact

This research was conducted to study the impact of foliar spraying by some plant growth regulators to increase salts tolerance of date palm (Phoenix dactylifera L.) cv. Shakar. Thirty young date palm trees (seven years old) and same number of fruiting trees (18 years old) were selected and spraying with naphthalene acetic acid (NAA) solutions at the concentrations (0.50, 100 and 150 ppm), Salicylic acid (0, 0.25, 0.50, and 1.0 mM) and putrescine (0, 0.025, 0.050, 0.1 mM). Results indicated that the application of growth regulators led to reduction trunk diameter comparing with control (121.33 cm). Spraying NAA with concentration of 100 ppm, gave the highest height of the offshoots and a significant difference from the rest of the treatments (253.70 cm). Spraying putrescine with 1.0 mM concentration led to a significant increase in the number of leaves (fronds) as it increased to 24.33 leaf/offshoot, and leaf area which reached 691 cm2. Application of 0.25 mM Salisylic acid increased the number of bunches under saline conditions amounted to 12.67 bunch as well as increased the weight of the fruit to 8.82 g, which differed significantly from the control which gave 7.37 g. As for the size of the fruit, it was found that Spraying of NAA with 100 ppm led to increase the size of the fruit under saline conditions (8.67 cm). We can conclude that the spraying date palm with the above plant growth regulators under saline conditions can lead to increasing absorption of nutrients and subsequent growth and yield improvement.

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The Improved Phytoextraction of Heavy Metals and the Growth of Trifolium repens L.: The Role of K2HEDP and Plant Growth Regulators Alone and in Combination

Sustainability ◽

10.3390/su13052432 ◽

2021 ◽

Vol 13 (5) ◽

pp. 2432

Author(s):

Anna Makarova ◽

Elena Nikulina ◽

Tatiana Avdeenkova ◽

Ksenia Pishaeva

Keyword(s):

Heavy Metals ◽

Plant Growth ◽

Plant Growth Regulators ◽

Growth Regulators ◽

Trifolium Repens ◽

Growth And Development ◽

Water Infiltration ◽

Iron Chelates ◽

Iron Chelate ◽

Trifolium Repens L

Heavy metals are among the most widespread pollutants in soil. Phytoextraction technology is used to solve the problem of multi-metal-contaminated soil. The efficiency of this process can be increased by introducing various amendments. A soil amendment is any material added to a soil to improve its physical properties, such as water retention, permeability, water infiltration, drainage, aeration, and structure. Some chemical amendments for enhanced phytoextraction, such as amino polycarboxylates chelators, can be hazardous to the environment and perform poorly at pH > 8. The effect of the potassium salt of hydroxyethylidene diphosphonic acid (K2HEDP), plant growth regulators (PGRs), and iron chelate alone and in combination on the phytoextraction by Trifolium repens L. seedlings of Cd, Ni, and Cu was studied in this work. K2HEDP works in a wider pH range. The results of this study confirmed that amino polycarboxylate chelators, with the sodium salt of ethylene diamine tetraacetic acid (Na2EDTA) as an example, have a pronounced negative effect on the growth and development (organ mass) of Trifolium repens L. seedlings. K2HEDP, proposed by the authors instead of Na2EDTA, produced a pronounced positive effect on plant growth and development, which was further enhanced by the use of PGRs and with iron chelates. However, it should be noted that K2HEDP showed significantly lower efficiency in trials on the Trifolium repens L. seedlings. The highest was the efficiency of K2HEDP with PGRs and iron chelates for the phytoextraction of Cd.

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Application of Plant Extracts in Micropropagation and Cryopreservation of Bleeding Heart: An Ornamental-Medicinal Plant Species

Agriculture ◽

10.3390/agriculture11060542 ◽

2021 ◽

Vol 11 (6) ◽

pp. 542

Author(s):

Dariusz Kulus ◽

Natalia Miler

Keyword(s):

Tissue Culture ◽

Plant Growth ◽

Plant Growth Regulators ◽

Growth Regulators ◽

Plant Extracts ◽

The Other ◽

White Gold ◽

Natural Extracts ◽

Other Hand ◽

The Impact

Lamprocapnos spectabilis (L.) Fukuhara (bleeding heart) is valued both in the horticultural and pharmaceutical markets. Despite its great popularity, information on the in vitro tissue culture technology in this species is limited. There is also little knowledge on the application of plant extracts in the tissue culture systems of plants other than orchids. The aim of this study is to compare the utility of traditional plant growth regulators (PGRs) and natural extracts—obtained from the coconut shreds, as well as oat, rice, and sesame seeds—in the micropropagation and cryopreservation of L. spectabilis ‘Gold Heart’ and ‘White Gold’. The biochemical analysis of extracts composition is also included. In the first experiment related to micropropagation via axillary buds activation, the single-node explants were cultured for a 10-week-long propagation cycle in the modified Murashige and Skoog medium fortified either with 1.11 µM benzyladenine (BA) and 1.23 µM indole-3-butritic acid (IBA) or with 10% (v/v) plant extracts. A PGRs- and extract-free control was also considered. In the cryopreservation experiment, the same 10% (v/v) extracts were added into the medium during a seven-day preculture in the encapsulation-vitrification cryopreservation protocol. It was found that the impact of natural additives was cultivar- and trait-specific. In the first experiment, the addition of coconut extract favoured the proliferation of shoots and propagation ratio in bleeding heart ‘Gold Heart’. Rice extract, on the other hand, promoted callus formation in ‘White Gold’ cultivar and was more effective in increasing the propagation ratio in this cultivar than the conventional plant growth regulators (4.1 and 2.6, respectively). Sesame extract suppressed the development of the explants in both cultivars analysed, probably due to the high content of polyphenols. As for the second experiment, the addition of plant extracts into the preculture medium did not increase the survival level of the cryopreserved shoot tips (sesame and oat extracts even decreased this parameter). On the other hand, coconut extract, abundant in simple sugars and endogenous cytokinins, stimulated a more intensive proliferation and growth of shoots after rewarming of samples. Analysing the synergistic effect of conventional plant growth regulators and natural extracts should be considered in future studies related to L. spectabilis.

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