# A xyloglucan endotransglucosylase/hydrolase gene, IbXTH16, increases cold tolerance in transgenic sweetpotato

## TL;DR

This study shows that the IbXTH16 gene improves cold tolerance in sweetpotato, helping plants survive low temperatures.

## Contribution

The IbXTH16 gene's role in enhancing cold tolerance through BR and proline pathways is newly identified in sweetpotato.

## Key findings

- IbXTH16 is induced by cold stress and brassinosteroid treatment.
- Overexpression of IbXTH16 increases cold tolerance in sweetpotato.
- IbXTH16 activates the BR and proline pathways to improve cold resistance.

## Abstract

Low temperature is a key environmental factor that threaten sweetpotato growth and development. In-depth studies on the gene functions underlying cold resistance are important for genetic engineering in sweetpotato.

The IbXTH16 gene was cloned using a homologous cloning approach. Its expression was detected in sweetpotato leaves subjected to low-temperature stress and brassinosteroid treatment. Subsequently, the IbXTH16 gene was introduced into sweetpotato variety Lizixiang to generate IbXTH16-overexpressing plants, thereby enabling the functional validation of the IbXTH16.

The IbXTH16 gene was cloned from the cold-tolerant variety LHS21. Its 879 bp coding sequence encoded a 292 aa protein with a molecular weight of 32.983 kDa and a pI of 8.47. The 2039 bp genomic sequence of IbXTH16 contained two exons and one intron. The IbXTH16 protein was localized in the cell membrane. IbXTH16 was strongly induced by 4°C and brassinosteroid. IbXTH16 positively regulates cold tolerance of sweetpotato by activating the BR and proline pathways.