PLANT GROWTH-PROMOTING BACTERIA FOR ENHANCING GROWTH, NUTRIENT USE AND RESILIENCE IN TEA (CAMELLIA SINENSIS)

Abstract

Tea (Camellia sinensis (L.) O. Kuntze) is an economically important perennial crop whose productivity and long-term performance depend strongly on successful plant establishment and efficient nutrient acquisition, particularly during the nursery stage. Tea is predominantly cultivated in acidic soils where phosphorus and potassium availability are restricted and where intensive use of chemical fertilizers can contribute to soil acidification, nutrient losses and deterioration of soil health. Plant growth-promoting microorganisms associated with the tea rhizosphere, phyllosphere and endosphere offer an important biological resource for improving plant growth, nutrient availability and stress tolerance. This review summarizes the current understanding of tea-associated beneficial microorganisms, with particular emphasis on biological nitrogen fixation, phosphate, potassium, zinc and silicate solubilisation, indole-3-acetic acid and siderophore production, ACC deaminase activity, biofilm and exopolysaccharide formation, and tolerance to acidic, saline and osmotic stresses. The review further examines the role of compatible microbial consortia in enhancing root development, seedling establishment, nutrient acquisition, and plant defence, together with their potential to reduce chemical fertilizer requirements. Particular attention is given to the complementary functions of nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and potassium-releasing bacteria as candidate components of a tea-adapted microbial consortium. Existing studies indicate that consortium-based inoculation can improve tea growth and nutrient-use efficiency and may facilitate partial replacement of chemical fertilizers. However, relatively few studies have developed microbial consortia specifically for tea nursery establishment using functionally complementary and mutually compatible indigenous microorganisms. Important gaps also remain concerning strain compatibility, acid tolerance, formulation stability, shelf life, fertiliser dose optimization and field-scale validation. Developing stable, tea-adapted microbial consortia therefore represents a promising strategy for improving seedling establishment, nutrient-use efficiency and the sustainability of tea production.