# PvARL1 Increases Biomass Yield and Enhances Alkaline Tolerance in Switchgrass (Panicum virgatum L.)

## TL;DR

A gene called PvARL1 helps switchgrass grow better and tolerate harsh soil conditions, making it a promising target for improving bioenergy crops.

## Contribution

The study identifies PvARL1 as a novel gene that enhances biomass yield and alkali tolerance in switchgrass.

## Key findings

- Overexpression of PvARL1 increases biomass yield and plant height in switchgrass under alkali stress.
- PvARL1 improves water content and photosynthetic stability while reducing cell damage under stress.
- PvARL1 helps reduce ion toxicity by affecting potassium levels in roots.

## Abstract

Switchgrass is an important bioenergy crop valued for its biomass yield and abiotic tolerance. Alkali stress is a major abiotic stress that significantly impedes plant growth and yield due to high salinity and pH; however, the response mechanism of switchgrass to alkali stress remains limited. Here, we characterized PvARL1, an ARF-like gene, which was up-regulated in both the shoot and root tissues under alkali stress conditions. Overexpression of PvARL1 not only improved alkali tolerance but also promoted biomass yield with more tiller and higher plant height in switchgrass. Moreover, PvARL1 overexpression lines displayed higher capacities in the maintenance of water content and photosynthetic stability compared with the controls under alkali treatments. A significant reduction in the ratio of electrolyte leakage, MDA content, and reactive oxygen species (ROS) showed that PvARL1 plays a positive role in protecting cell membrane integrity. In addition, PvARL1 also negatively affected the K+ efflux or uptake in roots to alleviate ion toxicity under alkali treatments. Overall, our results suggest that PvARL1 functions as a positive regulator in plant growth as well as in the plant response to alkali stress, which could be used to improve switchgrass biomass yield and alkali tolerance genetically.