Laxmi Rawat¹ , Tejpal Singh Bisht² , Akshit Kukreti³ , Matthew Prasad⁴

1 Division of Plant Pathology, College of Forestry, Ranichauri, Tehri Garhwal-249 199,V.C.S.G. Uttarakhand University of Horticulture and Forestry, Bharsar, Uttarakhand, India
2 Krishi Vigyan Kendra, Ranichauri, Tehri Garhwal-249 199, V.C.S.G. Uttarakhand University of Horticulture and Forestry, Bharsar, Uttarakhand, India
3 Department of Seed Science & Technology, College of Forestry, Ranichauri, Tehri Garhwal-249 199, V.C.S.G. Uttarakhand University of Horticulture and Forestry, Bharsar, Uttarakhand, India
4 V.C.S.G. Uttarakhand University of Horticulture and Forestry, Bharsar, Uttarakhand, India
Author    Correspondence author
Molecular Soil Biology, 2016, Vol. 7, No. 4   doi: 10.5376/msb.2016.07.0004
Received: 03 Jan., 2016    Accepted: 14 Feb., 2016    Published: 12 Jun., 2016

This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Laxmi Rawat, Tejpal Singh Bisht, Akshit Kukreti, and Matthew Prasad, 2016, Bioprospecting Drought Tolerant Trichoderma harzianum Isolates Promote Growth and Delay the Onset of Drought Responses in Wheat (Triticum aestivum L.), Molecular Soil Biology, 7(4): 1-15

The objectives of this study were to investigate whether seed biopriming through drought tolerant isolates of Trichoderma harzianum induces drought tolerance in wheat. Physiological and biochemical parameters were also monitored under greenhouse conditions to explore the mechanism underlying plant water stress resilience in response to Trichoderma inoculation.The impact of bioprospecting Trichoderma harzianum drought tolerant isolates, Rani Th-14, Rani Th-21, Rani Th-25, Rani Th-30 and Rani Th-39 on wheat response to drought was studied. Measurements of the stomatal conductance, net photosynthesis, chlorophyll fluorescence and greenness of plants were performed. In addition, analysis of the total phenolic compounds, free proline, MSI (membrane stability index) as well as lipid peroxidation was carried out. With or without exposure to drought conditions, colonization by Trichoderma isolates promoted seedling growth, the most consistent effect being an increase in shoot and root growth. The primary direct effect of colonization was promotion of root growth, regardless of water status, and an increase in water content, which it is proposed, caused a delay in many aspects of the drought response of wheat. Colonization of Trichoderma by seed biopriming enhanced drought tolerance of wheat plants as they delayed drought induced changes like stomatal conductance, net photosynthesis, chlorophyll fluorescence and greenness of plants. Drought stress from 4 to 13 d of withholding water induced an increase in the concentration of many stress induced metabolites in wheat leaves, while Trichoderma colonization caused a decrease in proline, MDA and H₂O₂ contents and an increase in phenolics concentration. Among different Trichoderma isolates, Rani Th-14 induced maximum drought tolerance as treated plants recorded only 20-40 per cent wilting even at 13 days drought stress (DDS). The study is important as the experiments confirmed that the drought tolerant isolates of Trichoderma through seed bio priming are critical in inducing tolerance to drought.

Drought stress; Trichoderma harzianum; Triticum aestivum; Free proline; Phenolics; Photosynthesis; Chlorophyll fluorescence