Work

Biochar and PGPR co-application mitigates salinity stress in Malabar spinach (Basella alba L.) by modulating growth, stress markers, and antioxidant defense

Year: 2026

Type: article

Abstract: Soil salinity is a major problem for agricultural productivity, adversely affecting plant growth, physiology, and biochemical performance. Malabar spinach ( Basella alba L. ), an important leafy vegetable with high nutritional value, is sensitive to salinity stress, leading to reduced yield and market quality. Developing sustainable strategies to mitigate these effects is essential for its cultivation in marginal soils. This study aimed to evaluate the individual and combined application of biochar and plant growth-promoting rhizobacteria (PGPR) in alleviating salt stress in B. alba . A greenhouse experiment was conducted using a completely randomized design with three factors: salinity (150 mM NaCl), biochar, and PGPR inoculation. Growth traits, biochemical attributes, ion homeostasis, and antioxidant enzyme activities were assessed. Results indicated that salinity significantly reduced non-enzymatic antioxidants (carotenoids, ascorbic acid, flavonoids, and phenolics) and elevated oxidative damage, as reflected by increased malondialdehyde (MDA). Proline accumulation increased as part of the osmotic adjustment response typical under salt stress. For example, 150 mM NaCl reduced plant height by approximately 36% and chlorophyll content by 30% compared with the control. The combined biochar + PGPR treatment improved plant height by 54% and chlorophyll levels by 39% relative to the salted control, while also lowering Na⁺ accumulation by 41%. Both amendments individually improved growth, RWC, K⁺/Na⁺ balance, and antioxidant enzyme activity under salinity, while the combined biochar + PGPR treatment produced the strongest recovery, showing the greatest improvements in pigment stability, ionic balance, and oxidative stress reduction. This work provides one of the first detailed evaluations of biochar–PGPR co-application in B. alba , demonstrating a practical biological strategy for improving crop tolerance in salt-affected systems.

Source: Scientific Reports

DOI: 10.1038/s41598-026-65993-5