Crustacean Meal Elicits Expression of Growth and Defense-Related Genes in Roots of Lettuce and Tomato

Abstract

Powdered crab and lobster shells (crustacean meal) obtained from fisheries are used as soil amendments to promote plant health and defense. In this study, a commercial crustacean meal amendment used to promote the health of lettuce, tomato, and other crop plants was applied to roots of lettuce and tomato seedlings. Gene expression profiling of the treated roots was assessed by RNA sequencing (RNA-seq) at 24 h after application relative to a 0 h time point. The RNA-seq analyses revealed upregulation of different types of genes in both tomato and lettuce roots at 24 h. Gene ontology analyses revealed increased expression of genes associated with oxidoreductases/metal ion binding in tomato roots at 24 h, while there was predominantly increased expression of genes associated with cell wall organization, lyases, and hydrolases in lettuce roots at 24 h. The types of defense-related genes expressed were also markedly different. In tomato roots, the most highly induced gene (log2 fold change 13.84, P ≤ 0.001) encoded a defense-associated miraculin-like protein, but transcripts of a similar gene were not induced in lettuce roots. Interestingly, phenylpropanoid pathway genes relating to cell wall biogenesis and lignification were significantly upregulated in both lettuce and tomato roots, suggesting that strengthening of plant cell walls is a common response to crustacean meal application. This research provides insight into gene expression patterns in the roots of lettuce and tomato in response to crustacean meal, improving our understanding of how this amendment could aid in plant health. [Figure: see text] The author(s) have dedicated the work to the public domain under the Creative Commons CC0 “No Rights Reserved” license by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law, 2022.

Keywords

• plant immune responses
• chitin
• gene expression
• lettuce
• tomato