Comparative proteomic analysis between mature and germinating seeds in Paris polyphylla var. yunnanensis

Li-Zhen Ling; Shu-Dong Zhang

doi:10.7717/peerj.13304

Comparative proteomic analysis between mature and germinating seeds in Paris polyphylla var. yunnanensis

PeerJ. 2022 May 11:10:e13304. doi: 10.7717/peerj.13304. eCollection 2022.

Authors

Li-Zhen Ling¹, Shu-Dong Zhang¹

Affiliation

¹ Key Laboratory of Liupanshui City for Study and Utilization of Ethnic Medicinal Plant Resources of Western Guizhou Province, Liupanshui Normal University, Liupanshui, China.

Abstract

The long dormancy period of Paris polyphylla var. yunnanensis seeds affects the supply of this scarce plant, which is used as an important traditional Chinese medicine. Mature seeds with a globular embryo and germinating seeds with developed embryo were used to explore the mechanisms of seed germination in this species. The protein profiles between the mature and germinating seeds were compared using the isobaric tags for relative and absolute quantification (iTRAQ) approach. Of the 4,488 proteins identified, a total of 1,305 differentially expressed proteins (DEPs) were detected. A Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of these DEPs indicated that metabolic pathways and the biosynthesis of secondary metabolites were the two top pathways. Additionally, phytohormone quantification shows that the abscisic acid (ABA) level significantly decreased, whereas the GA₃ level dramatically increased among nine endogenous gibberellins (GAs), resulting in a significant increase of the GA₃/ABA ratio in germinating seeds. The biosynthesis pathways of carotenoid as a precursor for ABA production and GA were further analyzed, and showed that proteinic expressions of the candidate genes in the two pathways did not correlate with the transcriptional abundances. However, 9-cis-epoxycarotenoid dioxygenase (NCED), a rate limited enzyme for ABA biosynthesis, was significantly decreased in mRNA levels in germinating seeds. By contrast, gibberellin 20-oxidase (GA20ox), a key enzyme GA biosynthesis, exhibited the major increase in one copy and a slight decrease in three others at the protentional level in germinating seeds. Gibberellin 2-oxidase (GA2ox), an inactivate enzyme in bioactive GAs, has the tendency to down-regulate in mRNA or at the proteinic level in germinating seeds. Altogether, these results suggested that the analyses of ABA and GA levels, the GA₃/ABA ratio, and the expressional patterns of their regulatory genes may provide a novel mechanistic understanding of how phytohormones regulate seed germination in P. polyphylla var. yunnanensis.

Keywords: Abscisic acid; Gibberellins; Paris polyphylla var. yunnanensis; Proteomics; Seed germination.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Abscisic Acid / metabolism
Germination* / genetics
Liliaceae* / metabolism
Plant Growth Regulators / metabolism
Proteomics
Seeds / genetics

Substances

Plant Growth Regulators
Abscisic Acid

Grants and funding

This work was supported by the Science and Technology Innovation Platform and Talent Team Construction Project of Liupanshui (No. 52020-2019-05-05) and Natural Science Research Project of the Education Department of Guizhou Province (No. QJHKYZ[2018]067). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.