CpBBX19, a B-Box Transcription Factor Gene of Chimonanthus praecox, Improves Salt and Drought Tolerance in Arabidopsis.

Huafeng Wu,Yinzhu Cao,Haiyuan Zhang,Xia Wang,Huamin Liu,Run Hua,Shunzhao Sui

doi:10.3390/genes12091456

Huafeng Wu, Yinzhu Cao + Show 5 more

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https://doi.org/10.3390/genes12091456

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Abstract

Zinc-finger proteins are important transcription factors in plants, responding to adversity and regulating the growth and development of plants. However, the roles of the BBX gene family of zinc-finger proteins in wintersweet (Chimonanthus praecox) have yet to be elucidated. In this study, a group IV subfamily BBX gene, CpBBX19, was identified and isolated from wintersweet. Quantitative real-time PCR (qRT-PCR) analyses revealed that CpBBX19 was expressed in all tissues and that expression was highest in cotyledons and inner petals. CpBBX19 was also expressed in all flower development stages, with the highest expression detected in early initiating bloom, followed by late initiating bloom and bloom. In addition, the expression of CpBBX19 was induced by different abiotic stress (cold, heat, NaCl, and drought) and hormone (ABA and MeJA) treatments. Heterologous expression of CpBBX19 in Arabidopsis thaliana (Arabidopsis) enhanced the tolerance of this plant to salt and drought stress as electrolyte leakage and malondialdehyde (MDA) concentrations in transgenic Arabidopsis after stress treatments were significantly lower than those in wild-type (WT) plants. In conclusion, this research demonstrated that CpBBX19 plays a role in the abiotic stress tolerance of wintersweet. These findings lay a foundation for future studies on the BBX gene family of wintersweet and enrich understanding of the molecular mechanism of stress resistance in wintersweet.

Highlights

Multiple sequence alignment revealed that the CpBBX19 protein sequence was highly homologous to the BBX19 protein sequence of Arabidopsis, Gossypium hirsutum, Hibiscus syriacus, Ziziphus jujuba, and Hevea brasiliensis (Figure 1a), indicating that BBX19 was conserved in plants
A phylogenetic tree of CpBBX19 and Arabidopsis BBX proteins was reconstructed by MEGE 6 (Figure 1b) and showed the five subfamilies of the BBX protein family; CpBBX19 belonged to the IV subfamily and was closely related to AtBBX19
There are no reports on the BBX gene family in wintersweet

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Wintersweet (Chimonanthus praecox), belonging to the Calycanthaceae family, is native to China, has a distinct flowering period (from November to March), strong aroma, and yellow flowers [1,2], and is widely used for cut flowers and as a garden plant in China [3]. Wintersweet is used for aromatic oil extraction, Chinese herbal medicine, and cosmetics [1,2,4]. The unusual flowering period of wintersweet shows that this species has a strong ability to tolerate low temperatures [5]. Some genes and transcription factors have been identified as related to biotic and abiotic stress in wintersweet [6]. Heterologous expression of CpSIZ1 in Arabidopsis enhanced the cold resistance of transgenic

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Conclusion