Genome-Wide Identification of BAHD Superfamily and Functional Characterization of Bornyl Acetyltransferases Involved in the Bornyl Acetate Biosynthesis in Wurfbainia villosa

Huilin Liang; Xiaojing Lin; Peng Yang; Yewen Sun; Qingwen Wu; Shamukaer Alimujiang; Haiying Zhao; Dongming Ma; Ruoting Zhan; Jinfen Yang

doi:10.3389/fpls.2022.860152

Genome-Wide Identification of BAHD Superfamily and Functional Characterization of Bornyl Acetyltransferases Involved in the Bornyl Acetate Biosynthesis in Wurfbainia villosa

Front Plant Sci. 2022 Mar 28:13:860152. doi: 10.3389/fpls.2022.860152. eCollection 2022.

Authors

Huilin Liang^{1

2}, Xiaojing Lin^{1

2}, Peng Yang^{1

2

3}, Yewen Sun^{1

2}, Qingwen Wu^{1

2}, Shamukaer Alimujiang², Haiying Zhao¹, Dongming Ma^{1

2}, Ruoting Zhan^{1

2}, Jinfen Yang^{1

2}

Affiliations

¹ Key Laboratory of Chinese Medicinal Resource from Lingnan (Ministry of Education), Guangzhou University of Chinese Medicine, Guangzhou, China.
² School of Pharmaceutical Science, Guangzhou University of Chinese Medicine, Guangzhou, China.
³ Hunan Provincial Key Laboratory for Synthetic Biology of Traditional Chinese Medicine, School of Pharmaceutical Sciences, Hunan University of Medicine, Huaihua, China.

Abstract

Bornyl acetate (BA) is known as a natural aromatic monoterpene ester with a wide range of pharmacological and biological activities. Borneol acetyltransferase (BAT), catalyzing borneol and acetyl-CoA to synthesize BA, is alcohol acetyltransferase, which belongs to the BAHD super acyltransferase family, however, BAT, responsible for the biosynthesis of BA, has not yet been characterized. The seeds of Wurfbainia villosa (homotypic synonym: Amomum villosum) are rich in BA. Here we identified 64 members of the BAHD gene family from the genome of W. villosa using both PF02458 (transferase) and PF07247 (AATase) as Hidden Markov Model (HMM) to screen the BAHD genes. A total of sixty-four WvBAHDs are distributed on 14 chromosomes and nine unanchored contigs, clustering into six clades; three WvBAHDs with PF07247 have formed a separated and novel clade: clade VI. Twelve candidate genes belonging to clade I-a, I-b, and VI were selected to clone and characterize in vitro, among which eight genes have been identified to encode BATs acetylating at least one type of borneol to synthesize BA. All eight WvBATs can utilize (-)-borneol as substrates, but only five WvBATs can catalyze (+)-borneol, which is the endogenous borneol substrate in the seeds of W. villosa; WvBAT3 and WvBAT4 present the better catalytic efficiency on (+)-borneol than the others. The temporal and spatial expression patterns of WvBATs indicate that WvBAT3 and WvBAT4 are seed-specific expression genes, and their expression levels are correlated with the accumulation of BA, suggesting WvBAT3 and WvBAT4 might be the two key BATs for BA synthesis in the seeds of W. villosa. This is the first report on BAT responsible for the last biosynthetic step of BA, which will contribute to further studies on BA biosynthesis and metabolism engineering of BA in other plants or heterologous hosts.

Keywords: BAHD gene family; Wurfbainia villosa; alcohol acetyltransferase; borneol acetyltransferase; bornyl acetate.