Deciphering the Role of Trehalose in Tripartite Symbiosis Among Rhizobia, Arbuscular Mycorrhizal Fungi, and Legumes for Enhancing Abiotic Stress Tolerance in Crop Plants

Abstract

Drought is a critical factor limiting the productivity of legumes worldwide. Legumes can enter into a unique tripartite symbiotic relationship with root-nodulating bacteria of genera Rhizobium, Bradyrhizobium, or Sinorhizobium and colonization by arbuscular mycorrhizal fungi (AMF). Rhizobial symbiosis provides nitrogen necessary for growth. AMF symbiosis enhances uptake of diffusion-limited nutrients such as P, Zn, Cu, etc., and also water from the soil via plant-associated fungal hyphae. Rhizobial and AMF symbioses can act synergistically in promoting plant growth and fitness, resulting in overall yield benefits under drought stress. One of the approaches that rhizobia use to survive under stress is the accumulation of compatible solutes, or osmolytes, such as trehalose. Trehalose is a non-reducing disaccharide and an osmolyte reported to accumulate in a range of organisms. High accumulation of trehalose in bacteroids during nodulation protects cells and proteins from osmotic shock, desiccation, and heat under drought stress. Manipulation of trehalose cell concentrations has been directly correlated with stress response in plants and other organisms, including AMF. However, the role of this compound in the tripartite symbiotic relationship is not fully explored. This review describes the biological importance and the role of trehalose in the tripartite symbiosis between plants, rhizobia, and AMF. In particular, we review the physiological functions and the molecular investigations of trehalose carried out using omics-based approaches. This review will pave the way for future studies investigating possible metabolic engineering of this biomolecule for enhancing abiotic stress tolerance in plants.

Ensifer aridi LMR001T Symbiosis and Tolerance to Stress Do Not Require the Alternative Sigma Factor RpoE2

“…Bacteria may respond by a modification in the transport and/or the metabolism of several molecules such as potassium ions, sugars, or amino acid derivatives that may act as compatible solutes to counteract osmotic pressure and/or protect bacteria against intracellular damages notably in rhizobia [12]. Among them, trehalose, a non-reducing disaccharide, appears promising as it may improve plant stress tolerance through symbiosis-mediated accumulation [13]. Bacteria may also trigger repair mechanisms to protect their macromolecules against damages by reactive oxygen species [14].…”

Trehalose can alleviate decreases in grain number per spike caused by low‐temperature stress at the booting stage by promoting floret fertility in wheat

“…Liu et al (2014) suggested that trehalose promotes water uptake in rice by inducing the expression of aquaporin. Sharma et al (2020) suggested that the improvement of trehalose on abiotic stress tolerance in legume related to microorganisms. Ponnu et al (2011) found that trehalose maintains normal growth of plants by regulating carbon and cell metabolism and activity cycle.…”

“…Sharma et al. (2020) suggested that the improvement of trehalose on abiotic stress tolerance in legume related to microorganisms. Ponnu et al.…”

Genome Features of Asaia sp. W12 Isolated from the Mosquito Anopheles stephensi Reveal Symbiotic Traits

“…Interestingly, these genomes also encode a trehalase (GH37) commonly found in various organisms ( Table S1 ). Trehalose plays a critical role as an energy source in insects, and it is involved in tolerating abiotic stresses [ 28 ]. The bacterial trehalase may contribute to the host carbon metabolism process and defense against osmotic and oxidative stress [ 29 ].…”