Synergistic potential of halophytes and halophilic/halotolerant plant growth-promoting bacteria in saline soil remediation: Adaptive mechanisms, challenges, and sustainable solutions

Abstract

Salinity stress poses significant challenges to agriculture, reducing productivity and limiting arable land by causing ionic and osmotic imbalances in plants, disrupting physiological processes, and leading to soil degradation over time. Halophytes and halophilic/halotolerant (HP/HT) plant growth-promoting bacteria (PGPB) offer sustainable solutions to mitigate saline stress and improve plant growth due to their adaptation to extreme environments through various mechanisms to tolerate high salinity, including ion homeostasis, osmotic balance, and the production of compatible solutes. However, understanding their synergistic interactions and specific salt adaptation strategies remains limited, impeding their application in saline soil remediation. This review examines the salt stress tolerance mechanisms of halophytes and HP/HT PGPB, highlighting their interactions and performance in saline environments. Halophyte and HP/HT PGPB demonstrate diverse mechanisms such as ion homeostasis, osmoprotection, and phytohormone modulation to enhance plant resilience to salt stress. Their synergistic interactions, facilitated by root exudates, chemical signaling, and hormone regulation, are vital for optimizing saline soil remediation and plant growth. The review also outlined challenges in utilizing halophyte-associated HP/HT PGPB for effective plant salt tolerance, discussing potential advancements through multi-omics approaches, genetic engineering, machine learning-assisted bioinformatics, chemometrics, and synthetic biology in sustainable agriculture. These integrated strategies offer valuable insights into salt stress tolerance mechanisms, paving the way for innovative applications of halophyte-HP/HT PGPB synergy in saline soil remediation and enhanced plant resilience, highlighting their role in promoting long-term agricultural sustainability.