# Dark septate endophytes promote the growth of Cynodon dactylon under drought stress and enhance its potential for use in the ecological restoration of slopes

## TL;DR

This study shows that dark septate endophytes help grass grow better under drought conditions, making it more useful for restoring slopes.

## Contribution

The study introduces the use of specific dark septate endophytes to improve drought tolerance in Cynodon dactylon for ecological restoration.

## Key findings

- DSEs increased dry weight, photosynthesis, and osmoregulatory substances in Cynodon dactylon under drought.
- DSEs reduced malondialdehyde content and enhanced antioxidant enzyme activity in drought-stressed plants.
- DSE inoculation improved plant resilience under both moderate and severe drought conditions.

## Abstract

The objective of this study was to investigate whether dark septate endophytes (DSEs) can increase plant drought tolerance in the context of vegetation concrete, which is a complex environment.

This study employed a controlled simulation experiment to investigate the influence of inoculation with diverse DSEs, namely, Paraphoma chrysanthemicola (PC), Alternaria alternata (AA), and Cladosporium cladosporioides (CC), on the growth, photosynthetic characteristics, osmoregulatory substance content, and antioxidant enzyme activities of Cynodon dactylon in vegetation concrete subjected to drought stress.

These findings demonstrated that DSEs were capable of effectively mitigating the adverse impacts of drought on plant growth. Under moderate drought (MD 55%±5% of the maximum moisture capacity in the field), DSEs increased the dry weight (DB), net photosynthetic rate (Pn), soluble sugar (SS) and peroxidase (POD) of C. dactylon by up to 14.21%, 32.63%, 40.73% and 31.43%, respectively, and reduced the malondialdehyde (MDA) content by 8.02-13.77%. Furthermore, under severe drought (SD, 35%±5% of the maximum moisture capacity in the field), DSE inoculation enhanced the photosynthetic capacity of C. dactylon, stimulated the accumulation of osmoregulatory compounds such as proline (Pro) and soluble protein (SP), and mitigated the water loss associated with drought.

The results demonstrate that DSE inoculation enhances the drought resistance of plants used in vegetation concrete by increasing the photosynthetic rate, and contents of antioxidant enzymes and osmoregulatory substances. This study provides reference for the use of DSEs in ecological restoration with vegetation concrete.