Multi-omics joint analysis reveals how Streptomyces albidoflavus OsiLf-2 assists Camellia oleifera to resist drought stress and improve fruit quality

Abstract

Camellia oleifera (C. oleifera) is a unique edible oil crop in China cultivated in the hilly southern mountains. Although C. oleifera is classified as a drought-tolerant tree species, drought remains the main factor limiting the growth of C. oleifera in summer and autumn. Using endophytes to improve crop drought tolerance is one effective strategy to meet our growing food crop demand. In this study, we showed that endophyte Streptomyces albidoflavus OsiLf-2 could mitigate the negative impact of drought stress on C. oleifera, thus improving seed, oil, and fruit quality. Microbiome analysis revealed that OsiLf-2 treatment significantly affected the microbial community structure in the rhizosphere soil of C. oleifera, decreasing both the diversity and abundance of the soil microbe. Likewise, transcriptome and metabolome analyses found that OsiLf-2 protected plant cells from drought stress by reducing root cell water loss and synthesizing osmoregulatory substances, polysaccharides, and sugar alcohols in roots. Moreover, we observed that OsiLf-2 could induce the host to resist drought stress by increasing its peroxidase activity and synthesizing antioxidants such as cysteine. A multi-omics joint analysis of microbiomes, transcriptomes, and metabolomes revealed OsiLf-2 assists C. oleifera in resisting drought stress. This study provides theoretical and technical support for future research on endophytes application to enhance the drought resistance, yield, and quality of C. oleifera.

Importance of Dark Septate Endophytes in Agriculture in the Face of Climate Change

“…Similarly, cellular stability occurs owing to the accumulation of the rigid and soluble osmolytes in water, which increases the osmotic pressure and causes minimal water loss. Galactose-rich heteropolysaccharide (GRH) induces the activation of the biochemical cascade necessary to maintain the hydric balance and increase the antioxidant defence [64][65][66]. Thus, the use of GRH in rice crops improved the superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activity levels while also reducing the malondialdehyde (MDA) content, which indicates the level of lipid oxidation in the membrane.…”

Comparison of Morphological, Physiological, and Related Gene Expression Responses to Drought Stress in Five Camellia vietnamensis Cultivars

“…Although this tree species has certain drought resistance, the growth and development of seedlings transplanted to mountainous areas during the dry season are often severely affected [35]. Without a sufficient water supply, the survival rate of seedlings will be greatly reduced [36,37]. At the same time, drought can also lead to a decrease in photosynthesis, oil content, flower buds and fruit setting of C. vietnamensis, and even lead to the death of drought-sensitive cultivars [37,38].…”

“…Without a sufficient water supply, the survival rate of seedlings will be greatly reduced [36,37]. At the same time, drought can also lead to a decrease in photosynthesis, oil content, flower buds and fruit setting of C. vietnamensis, and even lead to the death of drought-sensitive cultivars [37,38]. Therefore, understanding the differences in drought resistance among the main cultivated cultivars will contribute to the scientific cultivation and promotion of C. vietnamensis.…”