Evidence map›Paper›PMID 41909927›Full record

ArticlePlant biotechnology journal2026

Functional Characterisation of HAIRPLUS (NtHAP) Genes Involved in Trichome Development and Specialised Metabolism of Tobacco.

Hai Liu, Reid Farmer, Raja Payyavula, Chengalrayan Kudithipudi, Michael P Timko

Abstract read
In one paragraph

Article in Plant biotechnology journal, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors.

Hai LiuDepartment of Biology, University of Virginia, Charlottesville, Virginia, USA.
Reid FarmerDepartment of Biology, University of Virginia, Charlottesville, Virginia, USA.
Raja PayyavulaProduct Science & Technology, Altria Client Services LLC, Richmond, Virginia, USA.
Chengalrayan KudithipudiProduct Science & Technology, Altria Client Services LLC, Richmond, Virginia, USA.
Michael P TimkoDepartment of Biology, University of Virginia, Charlottesville, Virginia, USA.ORCID https://orcid.org/0000-0001-8258-7156

Funding

Altria Client Services, LLC GI15099
6 · The paper itself

Abstract

Plant glandular trichomes are specialised epidermal structures capable of synthesising, storing and secreting numerous varieties of secondary metabolites in different classes and are central to plant defence and the biosynthesis of high-value metabolites. In this study, we characterised the HAIRPLUS (HAP) gene family and uncovered its role as a conserved regulator of trichome development and metabolism in tobacco. Four homologues, NtHAP1a, NtHAP1b, NtHAP2a and NtHAP2b, were identified and functional studies using RNAi and CRISPR-Cas9 revealed that NtHAPs act as negative regulators of glandular trichome development. Suppression of NtHAPs resulted in increased trichome density and enlarged glandular heads, as well as enhanced accumulation of diterpenoids (e.g., neophytadiene) and increased nicotine levels. Additionally, NtHAP1 appeared to have a stronger effect on trichome density. This study establishes the NtHAP genes as key negative regulators of glandular trichome development in tobacco, expanding their functional scope from trichome morphogenesis to metabolic regulation and highlighting their evolutionary conservation across Solanaceae. These findings pave the way for both fundamental research into trichome biology and practical applications in metabolic engineering and crop improvement, such as pest resistance.

Indexed as

Genes, PlantNicotianaPlant ProteinsTrichomesCRISPR-Cas SystemsDiterpenesGene Expression Regulation, PlantNicotinePhylogenyPlants, Genetically ModifiedRNA InterferenceDiterpenesNicotinePlant ProteinsCRISPRglandular trichomeHAIRPLUS (HAP)RNAitobacco

Identifiers

PMID41909927
PMCPMC13278550

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.