Strategies for combating plant salinity stress: The potential of plant growth-promoting microorganisms

Authors: ACHARYA, BISWA - University Of California, Riverside; GILL, SATWINDER - Utah State University; KAUNDAL, AMITA - Utah State University; Sandhu, Devinder

Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/24/2024
Publication Date: 7/15/2024
Citation: Acharya, B., Gill, S.P., Kaundal, A., Sandhu, D. 2024. Strategies for combating plant salinity stress: The potential of plant growth-promoting microorganisms. Frontiers in Plant Science. 15:1406913. https://doi.org/10.3389/fpls.2024.1406913.
DOI: https://doi.org/10.3389/fpls.2024.1406913

Interpretive Summary: Salt stress is a major challenge for plants, affecting everything from seed germination and growth to flowering and yield, and can even lead to premature plant death. Salinity reduces water uptake by plants and causes an accumulation of harmful ions while disrupting the balance of essential ones, impacting plant health and nutrient acquisition. Additionally, salinity alters the levels of stress and growth hormones, further inhibiting growth. In these harsh conditions, certain microorganisms known as plant growth-promoting microorganisms (PGPMs) can be lifesavers. This review talks about how PGPMs help plants deal with salt by helping them get more water, balancing harmful substances, and making sure they get the nutrients they need. PGPMs can also help plants grow by giving them hormones and boosting their ability to fight stress. The use of PGPMs in farming is a big deal because it offers a way to make crops stronger against salt stress in an environmentally friendly way. Thanks to new research and technologies like computer models and editing genes, we can get even more out of PGPMs. This means we could make crops that do better in salty conditions, leading to better growth and more food. To really tackle the problem of salt stress in plants, we need experts from different fields like soil science, water chemistry, plant science, genetics, and farming to work together. This review helps students and researchers learn more about how PGPMs can fight salt stress in plants. This is important for growing enough food for everyone around the world.

Technical Abstract: Salinity represents a significant abiotic stressor that detrimentally influences plant physiology and gene expression, leading to adverse effects on critical processes such as seed germination, growth, development, and yield. Salinity severely impacts crop yields, as many crop plants are sensitive to salt stress. Global climate change and less availability of good quality water cause more agricultural areas to become saline. Plant growth-promoting microorganisms (PGPMs) in the rhizosphere or the rhizoplane of plants are considered the “second genome” of plants as they contribute significantly to improving the plant growth and fitness of plants in normal and when plants are under stress such as salinity. PGPMs are crucial in assisting plants to navigate the harsh conditions imposed by salt stress. By enhancing water and nutrient absorption, which is often hampered by high salinity, these microorganisms significantly improve plant resilience. They bolster the plant's defenses by increasing the production of osmoprotectants and antioxidants, mitigating salt-induced damage. Furthermore, PGPMs supply growth-promoting hormones like auxins and gibberellins and reduce levels of the stress hormone ethylene, fostering healthier plant growth. Importantly, they activate genes responsible for maintaining ion balance, a vital aspect for plant survival in saline environments. This review underscores the multifaceted roles of PGPMs in supporting plant life under salt stress, spotlighting their value for agriculture in salt-affected areas and their potential impact on global food security.