Pushp Sheel Shukla1*, Nivetha Nagarajan1, Sri Sailaja Nori1, Sawan Kumar1, and Shrikumar Suryanarayanan1
1Research and Development Division, Sea6 Energy Private Limited, 1st Floor, Centre for Cellular and Molecular Platforms, NCBS-TIFR Campus, GKVK Bellary Road, Bengaluru, Karnataka, 560095
Correspondence: Pushp Sheel Shukla, pushp.shukla@sea6energy.com
To feed the growing population, the agricultural productivity must be doubled by 2050. In current scenario, the agricultural domain is basically relying on extensive use of chemical fertilisers to increase growth and productivity of plants. Biostimulants are the new class of sustainable agriculture inputs that are known to have beneficial effect on plant growth and productivity. In this study we have demonstrated that Kappaphycus alvarezii derived biostimulant, AgroGain®, rich in sulphated galacto-oligosaccharides, induces the expansion of the cucumber cotyledon. After 7 days of treatment, AgroGain® supplemented cotyledons show 29.2% increase in area of expanded cotyledon as compared to control. The gene expression analysis carried out on cucumber cotyledon revealed that AgroGain® treated cotyledon differentially modulated the expression of genes involved in cell division, cell number, cell expansion, cell size, and phytohormone biosynthesis. Further, foliar spray of the AgroGain® on the cucumber plants grown under hydroponics conditions shows improved plant growth as compared to control. Total leaf area of AgroGain® sprayed plants was increased by 19.1% than the control. Photosynthetic efficiency of AgroGain® sprayed cucumber plants was found to be higher via increased photochemical quenching and reduced non-photochemical and non-regulatory quenching. AgroGain® application also modulated change in the steady state photosynthetic parameters in cucumber leaves. The rate of linear electron flux (LEF), proton conductivity (gH+) and steady-state proton flux (vH+) across the thylakoid membrane was found higher in AgroGain® sprayed plants, suggesting that bioactive compounds present in AgroGain® improves the growth of cucumber plants by regulating the physiological and developmental pathways.