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.

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.

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