Piriformospora indica Improves Drought Tolerance in Tomato Plants through Enhanced Nutrient Uptake and Antioxidant Enzymes

Piriformospora indica, a beneficial root endophytic basidiomyceteous fungus, has demonstrated the ability to enhance plant growth and increase tolerance to stressful conditions, particularly drought and salinity. This study aimed to examine the effectiveness of P. indica in mitigating the negative effects of drought stress in tomato plants. In a greenhouse pot experiment, tomato plants colonized with P. indica (P1) and non-inoculated with P. indica (P2) were subjected to different water regimes, including well-watered conditions and varying levels of drought stress (D1 - Control (100% Field Capacity - FC), D2 - 75% FC, D3 - 50% FC and D4 - 25% FC). The study evaluated multiple parameters such as, yield per plant, anti-oxidant enzyme activities and nutrient uptake as influenced by P. indica-colonization and drought stress. The results revealed that as the drought stress increased, micro- and macro- nutrients uptake got reduced, leading to a reduction in yield. But this reduction was found to be less in P. indica-colonized plants compared to the control plants indicating the positive effect of colonization on nutrient uptake and yield per plant. Drought stress increased the accumulation of anti-oxidant enzymes and proline in tomato plants, which is a method of drought tolerance and mitigating mechanism. However, P. indica-colonization resulted in significantly higher anti-oxidants compared to control plants corresponding to same level of drought stress indicating the role of the endophyte in drought tolerance in tomato plants through improved antioxidant enzyme activities and proline content.