Endophytes are non-disease causing microbes (bacteria and fungi) surviving in living tissues of plants. Their intimate association and possible coevolution with their plant partners have resulted in them contributing to an array of plant growth benefits ranging from enhanced growth and biomass accumulation, tolerance to abiotic and biotic stresses and in nutrient acquisition. The last couple of decades have witnessed a burgeoning literature on the role of endophytes (Class 3 type) in regulating plant growth and development and their adaptation to abiotic and biotic stresses. Though the underlying mechanisms of plant-endophyte interactions are far from clear, several studies have raised the hope of their potential application in agriculture, especially in mitigating abiotic and biotic stresses. The use of endophytes is envisaged as a route to reduce the production cost and burden on the environment by lessening the dependence on breeding for crop improvement and agrochemicals. Unfortunately, save a few well documented examples of their use, a little of these insights has been translated into actual agricultural applications. Here, we reflect on this paucity and elaborate on some of the important bottlenecks that might stand in way of fully realizing the potential that endophytes hold for crop improvement. We stress the need to study various facets of the endophyte-plant association for their gainful application in agriculture.

内生细菌是非疾病引起的在植物的活组织中存活的微生物（细菌和真菌）。它们与植物伙伴的密切联系以及可能的共同进化导致它们为一系列植物生长做出了贡献，包括增强的生长和生物量积累，对非生物和生物胁迫的耐受性以及养分吸收。在过去的几十年中，有关内生菌（3类）在调节植物生长和发育以及适应非生物和生物胁迫方面的作用的文献不断增多。尽管植物与内生植物相互作用的潜在机制尚不清楚，但一些研究已经提出了其在农业中潜在应用的希望，尤其是在缓解非生物和生物胁迫方面。设想将内生菌的使用作为通过减少对作物改良和农用化学品的育种的依赖来降低生产成本和对环境造成负担的途径。不幸的是，除了一些有据可查的使用示例外，这些见解中的一小部分已转化为实际的农业应用。在这里，我们对这种匮乏进行了反思，并阐述了一些重要的瓶颈，这些瓶颈可能会阻碍充分认识到内生植物为作物改良所具有的潜力。我们强调有必要研究内生植物-植物协会的各个方面，以将其有益地应用于农业。这些见解中的一小部分已转化为实际的农业应用。在这里，我们对这种匮乏进行了反思，并阐述了一些重要的瓶颈，这些瓶颈可能会阻碍充分认识到内生植物为作物改良所具有的潜力。我们强调有必要研究内生植物-植物协会的各个方面，以将其有益地应用于农业。这些见解中的一小部分已转化为实际的农业应用。在这里，我们对这种匮乏进行了反思，并阐述了一些重要的瓶颈，这些瓶颈可能会阻碍充分认识到内生植物为作物改良所具有的潜力。我们强调有必要研究内生植物-植物协会的各个方面，以将其有益地应用于农业。