Evaluation of Differentially Expressed Genes in Leaves vs. Roots Subjected to Drought Stress in Flax (Linum usitatissimum L.)

Abstract

Drought stress is a common environmental challenge that plants face, severely constraining plant growth and reducing crop yield and quality. Several studies have highlighted distinct responses between monocotyledonous and dicotyledonous plants. However, the mechanisms underlying flax tolerance to abiotic stress, such as drought, remain unclear. In this study, we investigated the morphological, physiological, and biochemical characteristics and the genome-wide gene expression of oil flax and fiber flax in response to drought stress. The results revealed that drought stress caused significant wilting of flax leaves. Within the first 24 h of stress, various physiological and biochemical characteristics exhibited rapid responses. These included fresh weight, relative water content (RWC), proline, soluble protein, soluble sugar, superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in the leaves or roots of flax. Additionally, drought stress led to a significant rise in lignin content in fiber flax. In addition, the transcriptome analysis demonstrated genome-wide variations in gene expression induced by drought stress. Specifically, genes associated with photosynthesis, proline biosynthesis, and phytohormone metabolism exhibited significant differences in expression levels under stress conditions in flax. These findings highlight the rapid response of flax to drought stress within a short-term period. Our experiment also revealed that, although there were variations in the levels of small compound content or gene expression between Longya10 and Fany under drought stress, most stress-resistance responses were similar. Furthermore, the results provide additional evidence supporting the existence of mechanisms underlying the response to drought stress in plants.

Gene Expression Analysis of Different Organs and Identification of AP2 Transcription Factors in Flax (Linum usitatissimum L.)

“…It was utilized to improve flax crops’ fiber quality and yield [ 63 , 64 ]. In the previous study, we identified differentially expressed genes and enriched pathways related to stress response, hormone signaling, and physiological characteristics, which can be applied to develop drought-tolerant flax varieties and enhance crop productivity under water-limited conditions [ 65 ]. Furthermore, in the previous report, the gene expression profiles of flax seeds during development and identified genes involved in fatty acid biosynthesis and seed storage, which are used to enhance the oil content and quality of flax seeds, are important for various industrial applications [ 66 , 67 ].…”

Exogenous Hydrogen Sulfide increased Nicotiana tabacum L. resistance against drought by the improved photosynthesis and antioxidant system

“…Drought stress also profoundly affects plant organelles and ultrastructures, including chloroplasts, which may undergo expansion, rupture, disintegration, and alterations in plastid and starch grain number and size 5 . Furthermore, changes in antioxidant and enzyme activities occur under drought stress 6 , alongside regulating the expression of drought-resistance-related genes 7,8 . Moreover, drought stress has been documented to affect the accumulation of various osmolytes or metabolites, including glycine betaine, polyols, polyamines, and proline.…”