Integrating Transcriptional, Metabolic, and Physiological Responses to Drought Stress in Ilex paraguariensis Roots

Abstract

The appearance of water stress episodes triggers leaf abscission and decreases Ilex paraguariensis yield. To explore the mechanisms that allow it to overcome dehydration, we investigated how the root gene expression varied between water-stressed and non-stressed plants and how the modulation of gene expression was linked to metabolite composition and physiological status. After water deprivation, 5160 differentially expressed transcripts were obtained through RNA-seq. The functional enrichment of induced transcripts revealed significant transcriptional remodelling of stress-related perception, signalling, transcription, and metabolism. Simultaneously, the induction of the enzyme 9-cis-expoxycarotenoid dioxygenase (NCED) transcripts reflected the central role of the hormone abscisic acid in this response. Consequently, the total content of amino acids and soluble sugars increased, and that of starch decreased. Likewise, osmotic adjustment and radical growth were significantly promoted to preserve cell membranes and water uptake. This study provides a valuable resource for future research to understand the molecular adaptation of I. paraguariensis plants under drought conditions and facilitates the exploration of drought-tolerant candidate genes.

Identification and Expression Profile of NCED Genes in Arachis hypogaea L. during Drought Stress

“…In addition, AhNCED1 contains two MeJA elements and one SA element, while AhNCED2 contains one SA element (Table S2). ABA can interact with hormones such as MeJA and SA [16]. Therefore, the expression levels of AhNCED1 and AhNCED2 were significantly upregulated under 20% PEG6000-induced drought stress in the NH5 (drought-tolerant) and FH18 (drought-sensitive) cultivars (Figure 9).…”

“…Long-term studies have shown that the endogenous hormone abscisic acid (ABA) is intricately linked to regulating drought resistance in some plants [7][8][9][10][11][12]. Furthermore, in some plants, NCED genes related to ABA synthesis were critical involvement in drought resistance mechanisms [13][14][15][16]. For instance, the overexpression of OsNCED5 in Oryza sativa has been shown to increase ABA levels, enhance tolerance to drought stress, and accelerate leaf senescence [14].…”