Unraveling the mystery of lignosuberization: A comprehensive study of periderm formation in sikkim cucumber fruit skin
image: The Sikkim cucumber fruit undergoes massive skin cracking during development.
Credit: Horticulture Research
In fleshy fruits, periderm tissue often forms on the skin surface as a response to mechanical damage caused following environmental cues or developmental programs, known as lignosuberization, creating a protective, corky matrix. This process, vital for maintaining skin integrity and protecting against environmental insults, is not fully understood. Previous studies have indicated that epidermal cell layer alters the fruit's skin chemistry and morphology, involving complex polymers like suberin and lignin. However, the precise biochemical pathways and triggers for lignosuberization remain largely unknown.
In April 2022, Horticulture Research published a research entitled by “The metabolic and proteomic repertoires of periderm tissue in skin of the reticulated Sikkim cucumber fruit”. In this study, researchers employed microscopy, metabolomics, and proteomics to investigate the development of Sikkim cucumber fruit skin, particularly focusing on the cracking phenomenon associated with lignosuberization.
Firstly, researchers performed investigation of seven stages along the Sikkim cucumber’s fruit development at tenday intervals; from 10 days after fertilization (DAF) to 70 DAF (Fig.1). From 30 DAF until full maturity, the extent of cracking increased and the fractures widened and deepened. The results also showed that skin cracking in the Sikkim cucumber fruit was related to the formation of a typical wound periderm tissue. Then, microscopic investigations indicated a large portion of cells that form the wound periderm tissue in the Sikkim cucumber fruit is both lignified and suberized. Further, researchers subjected skin tissue from the seven investigated developmental stages to comparative profiling via GC–MS and UPLC-HRMS. Periderm tissue formation is principally associated with over-accumulation of suberin components, phenylpropanoids, flavonoids and ceramides, along with reduced amounts of membrane components and storage lipids. To obtain insight into mechanisms involved in the initiation and regulation of lignosuberized periderms, comparative proteomics profiling of skin tissues along fruit development was carried out. Gene Ontology (GO) analysis found proteins belonging to fatty acid biosynthesis, as well as aromatic amino acid, phenylpropanoid, suberin, lignin and indolalkylamine pathways; their corresponding encoding genes had been previously tightly linked with periderm tissue formation. Finality, the accumulation of proteins associated with lipid metabolism, cell wall modification, vesicle-mediated trafficking and stress responses during the formation of periderm were found.
In conclusion, this study's multi-omic approach, pairing detailed structural observations with in-depth molecular analyses, provides a rich catalog of metabolic and protein changes associated with periderm formation in the Sikkim cucumber. It highlights the intricate balance and regulation of cutin, suberin, and lignin pathways in developing fruit skin and sets a foundation for further understanding of fruit skin resilience and adaptation mechanisms.
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References
Authors
Gulab Chand Arya1,†, Yonghui Dong2,†, Uwe Heinig2,3,†, Nir Shahaf2, Yana Kazachkova2, Elinor Aviv-Sharon2, Gal Nomberg1,4, Ofir Marinov1,4, Ekaterina Manasherova1, Asaph Aharoni2 and Hagai Cohen1,*
†Equally-contributing authors
Affiliations
1Department of Vegetable and Field Crops, Institute of Plant Sciences, Agricultural Research Organization (ARO), Volcani Center, Rishon Lezion 7505101, Israel
2Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel
3Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot 7610001, Israel
4Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel
About Hagai Cohen
The Cohen lab investigates various aspects of interactions between plant surfaces (such as the cuticle, epicuticular waxes, suberin and lignin) and pathogens. Particularly, they focus on metabolic networks operating on the course of pathogen attack and invasion.