ACC deaminase-producing endophytic fungal consortia promotes drought stress tolerance in M.oleifera by mitigating ethylene and H2O2

Abstract

IntroductionDrought has become more prevalent due to dramatic climate change worldwide. Consequently, the most compatible fungal communities collaborate to boost plant development and ecophysiological responses under environmental constraints. However, little is known about the specific interactions between non-host plants and endophytic fungal symbionts that produce growth-promoting and stress-alleviating hormones during water deficits.MethodsThe current research was rationalized and aimed at exploring the influence of the newly isolated, drought-resistant, ACC deaminase enzyme-producing endophytic fungi Trichoderma gamsii (TP), Fusarium proliferatum (TR), and its consortium (TP+TR) from a xerophytic plant Carthamus oxycantha L. on Moringa oleifera L. grown under water deficit induced by PEG-8000 (8% osmoticum solution).ResultsThe current findings revealed that the co-inoculation promoted a significant enhancement in growth traits such as dry weight (217%), fresh weight (123%), root length (65%), shoot length (53%), carotenoids (87%), and chlorophyll content (76%) in comparison to control plants under water deficit. Total soluble sugars (0.56%), proteins (132%), lipids (43%), flavonoids (52%), phenols (34%), proline (55%), GA3 (86%), IAA (35%), AsA (170%), SA (87%), were also induced, while H2O2 (-45%), ABA (-60%) and ACC level (-77%) was decreased by co-inoculation of TP and TR in M. oleifera plants, compared with the non-inoculated plants under water deficit. The co-inoculum (TP+TR) also induced the antioxidant potential and enzyme activities POX (325%), CAT activity (166%), and AsA (21%), along with a lesser decrease (-2%) in water potential in M. oleifera plants with co-inoculation under water deficit compared with non-inoculated control. The molecular analysis for gene expression unraveled the reduced expression of ethylene biosynthesis and signaling-related genes up to an optimal level, with an induction of antioxidant enzymatic genes by endophytic co-inoculation in M. oleifera plants under water deficit, suggesting their role in drought stress tolerance as an essential regulatory function.ConclusionThe finding may alert scientists to consider the impacts of optimal reduction of ethylene and induction of antioxidant potential on drought stress tolerance in M. oleifera. Hence, the present study supports the use of compatible endophytic fungi to build a bipartite mutualistic symbiosis in M. oleifera non-host plants to mitigate the negative impacts of water scarcity in arid regions throughout the world.

Trichoderma Inoculation Alleviates Cd and Pb-Induced Toxicity and Improves Growth and Physiology of Vigna radiata (L.)

“…The ACC deaminase enzyme is released by a variety of soil microorganisms, including bacteria and fungi . This enzyme is essential for lowering ethylene (ET) in plants and fostering plant growth even under challenging circumstances.…”

The plant endomicrobiome: Structure and strategies to produce stress resilient future crop

“…Soil salinity is an issue of great importance in relation to irrigation and agricultural production in arid and semiarid regions ( Vimal et al, 2023a ; b). Drought stress is a multidimensional stress and causes changes in the physiological, morphological, biochemical, and molecular traits in plants ( Rehman et al, 2022 ). Temperature stresses as high, chilling and freezing stress disrupt photosynthesis and increase photorespiration thereby altering the normal homoeostasis of plant cells ( Singh and Vimal, 2020 ; Vimal et al, 2023a ).…”

“… Kosteletzkya virginica Trichoderma viride ACC deaminase Enhanced plant growth parameters, chlorophyll contents, and antioxidants activities Wang et al (2023) 12. Cathamus oxycantha Trichoderma gamsii and Fusarium proliferatum ACC deaminase Manages plant health under drought stressed plants Rehman et al (2022) 13. Rhizobium sp.…”

Microbial modulation of hormone signaling, proteomic dynamics, and metabolomics in plant drought adaptation

“…Advancing our comprehension of the potential of endophytic fungi, Rehman et al. (2022) investigated the impact of drought‐resistant endophytic fungi, Trichoderma gamsii and Fusarium proliferatum , on Moringa oleifera L., a medicinal plant. These fungi synthesized growth‐promoting hormones and osmolytes, resulting in enhanced germination, growth, and nutrient uptake.…”