Implementation of CsLIS/NES in linalool biosynthesis involves transcript splicing regulation in Camellia sinensis

Area of Science:

• Plant biochemistry
• Molecular biology
• Chemical ecology

Background:

• Volatile terpenoids in tea plants (Camellia sinensis) serve ecological roles and contribute to tea aroma.
• Transcription regulation, including transcript processing, is crucial for controlling plant volatile terpenoid biosynthesis.
• A specific terpene synthase gene, CsLIS/NES, was identified in Camellia sinensis cv. "Long-Men Xiang".

Purpose of the Study:

• To investigate the transcription regulation of the CsLIS/NES gene in tea plants.
• To determine the distinct functions and localization of different CsLIS/NES splicing forms.
• To understand how these isoforms contribute to volatile terpenoid production and stress response.

Main Methods:

• Gene recovery and analysis of splicing forms (CsLIS/NES-1 and CsLIS/NES-2).
• In vitro enzymatic activity assays to determine product specificity.
• Transgenic tobacco studies and antisense oligo-deoxynucleotide suppression in tea leaves to assess gene function and localization.
• Analysis of gene expression patterns and response to methyl jasmonate treatment.

Main Results:

• Two splicing forms, CsLIS/NES-1 and CsLIS/NES-2, were identified, both producing (E)-nerolidol and linalool in vitro.
• CsLIS/NES-1, localized in chloroplasts, functions as linalool synthase.
• CsLIS/NES-2, localized in the cytosol, functions as a potential nerolidol synthase.
• CsLIS/NES-1 expression is induced by methyl jasmonate, while CsLIS/NES-2 is not.
• Distinct expression patterns and subcellular localization of the two isoforms were observed.

Conclusions:

• Distinct transcript splicing and subcellular compartmentation of CsLIS/NES-1 and CsLIS/NES-2 regulate linalool biosynthesis in tea plants.
• These regulatory mechanisms respond to both endogenous and exogenous factors, including stress signals like methyl jasmonate.
• The findings provide insight into the complex control of volatile terpenoid production in tea plants.