Bacterial and Fungal Endophytes: Tiny Giants with Immense Beneficial Potential for Plant Growth and Sustainable Agricultural Productivity

The conventional means of achieving enhanced agricultural productivity are not ecologically balanced and sustainable. The excessive use of synthetic agrochemicals, declining soil nutrients, and water-use issues, amongst others, are threats to the ecosystem. Additionally, environmental degradation and an increasing global population that will reach 9 billion by 2030 are further considerations. These issues mean a decline in the volume of food resources available to feed the world. Therefore, sustainably increasing agricultural productivity is a necessity for restoring soil fertility, feeding the populace, and improving the ecosystem. A way to achieve this is by using eco-friendly microbial inoculants. Endophytes inhabit the tissues of plants asymptomatically without causing adverse effects. Bacterial and fungal endophytes benefit plants by promoting growth, suppressing pathogens, and improving the stress tolerance and immunity of plants. Despite this vital role played by endophytes in their interactions with host plants, there is still a paucity of relevant review data. More importantly, the prospective use of endophytes as an alternative to synthetic agrochemicals to ensure agro-ecological crop productivity has not been well reviewed in the literature. Therefore, this review sought to highlight the potential use of endophytic microbial resources to achieve enhancements in agro-food system crops in a sustainable manner.