Cumulative effect of gibberellic acid and phosphorus on crop productivity, biochemical activities and trigonelline production in Trigonella foenum-graecum L.

Abstract

Fenugreek (Trigonella foenum-graecum L.) is an antidiabetic plant. Its bioactive compound, trigonelline, is known to counter diabetes through insulin secretion, modulation of β cell regeneration and quick activity of glucose metabolism related enzymes. A pot experiment was conducted in the natural conditions of net house of the Department of Botany, Aligarh Muslim University, Aligarh (UP), India, to evaluate the effect of four concentrations of GA₃ (0, 10⁻⁷ M, 10⁻⁶ M and 10⁻⁵ M), alone and in combination with phosphorus (40 kg P ha⁻¹), on growth, biochemical and yield attributes of fenugreek. Compared to control, the combination of GA₃ and phosphorus (P40 + 10⁻⁶ M GA3) significantly increased the activities of nitrate reductase (30.8%) and carbonic anhydrase (30.7%) enzymes; it also enhanced the seed yield (140.6%) and the content of total chlorophyll (28.5%) and carotenoids (26%). There was also significant increase (19.51%) in the content of seed trigonelline.

Keywords:

• biochemical
• high performance liquid chromatography
• diabetes mellitus
• yield
• carbonic anhydrase
• nitrate reductase

Public Interest Statement

Trigonella foenum-graecum L., commonly known as fenugreek, is an annual herb belonging to the family Leguminosae. It is used as an antidiabetic plant. It contains bioactive compounds as trigonelline, diosgenin, 4-hydroxyisoleucine (4-HI), galactomannan flavonoids, carotenoids, coumarins, saponins and lipids. Diosgenin is used by pharmaceutical and nutraceutical industries as a precursor for the production of steroidal drugs and hormones such as testosterone, progesterone and glucocorticoids. Diabetic patients are recommended to take fenugreek as a vegetable in diet. Being such an immense medicinal plant, there is a need to enhance the growth and active constituents of this plant. Gibberellic acid (GA₃) is a plant growth hormone (C₁₉H₂₂O₆) that regulates seed germination, stem elongation, leaf expansion, fruit development, flowering and stimulation of secondary metabolite production in plants. In the present study, the foliar application of GA₃ in combination with soil applied phosphorus enhanced growth, biochemical attributes and yield of fenugreek. It significantly enhanced the trigonelline production as well.

Cover image

Source: Author.

Additional information

Funding

Funding. University Grants Commission (UGC), New Delhi, India provided the fellowship to the first author, while the Department of Botany, Aligarh Muslim University, Aligarh provided the facilities for conducting this research work. Both the organizations are highly acknowledged regarding this research work.

Notes on contributors

Tariq Ahmad Dar

Our research group deals with Plant Physiology and Biochemistry with a thrust on the study “Effect of plant growth regulators, mineral nutrients, nanoparticles and marine polysaccharides on growth, physiology and secondary metabolite production of medicinal and aromatic plants”.

The present work shows that the combined application of gibberellic acid and phosphorus significantly enhanced the growth, physiological activities and trigonelline production in Trigonella foenum-graecum L. Further research is needed to find how GA₃ acts at molecular level to increase the production of trigonelline in this plant.