Endophytic Seed Bacteria: A Relevant Pool of Microorganisms with the Ability to Promote Plant Growth

Abstract

According to the Food and Agricultural Organization (FAO), “global agricultural production needs to increase by 70% and double in developing countries by 2050 to meet the demand of 9 billion people”. The major challenge all countries are currently facing in the world is food security. It is connected to two inseparable components, namely, land and water. In a context of agro-ecological transition, many actors including those of research are mobilized to develop sustainable solutions. These include the use of biofertilizers of microbial origin. Microbial biofertilizers are a sustainable alternative to currently widely used inputs. In contrast to these, biofertilizers ensure plant productivity and conservation of water, soil and biodiversity resources. Moreover, their use does not impact human health. Plants can be described as complex micro-ecosystems to which the different habitats are exploited by a wide variety of bacteria. Endophytes are non-pathogenic organisms that perform part or all of their life cycle within plant tissues. Endophytic bacteria are likely to have beneficial effects similar to the known effects of plant growth-promoting rhizobacteria (PGPR). A number of studies evoke the interest of endophytic bacteria, but only a few bring up the topic of seed endophytic bacteria. Hence, seeds are essential tools for agricultural production, as well as potential supports for endophytic bacteria. This chapter aims to highlight the potentialities of the seed-borne endophytic bacteria for agricultural use due to their remarkable abilities (survival in extreme conditions, motility, competitive advantage, vertical transmission, contribution to germination, growth-promoting effects, biocontrol abilities). The examples mentioned for the different kind of cultures (market gardening, big cultures, forage crops, niche market cultures) demonstrate the relevance of agricultural purposes.KeywordsEndophytic bacteriaBiofertilizersBiopesticidesAgro-ecologyPGPR