Transcriptome analysis reveals the physiological and transcriptional responses associated with growth promotion by N-acetyl-L-thiazolidine-4-carboxylic acid (NATCA) in wheat plants.

UNLABELLED: N-acetyl-L-thiazolidine-4-carboxylic acid (NATCA) is an organic amino acid derivative that functions as a plant growth regulator, enhancing growth and nutrient utilization in fruit trees and various crops. However, the molecular responses underlying its growth-promoting effects remain poorly understood. Here, we demonstrate that NATCA significantly promotes the growth and development of wheat (Triticum aestivum), with application at different concentrations enhancing physiological performance in stems, leaves, and roots. Treatment with 0.7 mg/L NATCA yielded the most pronounced positive effects. Under this treatment, chlorophyll content, free amino acids (FAA), soluble protein (SP), fresh weight, and dry weight all significantly increased compared to the control. Furthermore, NATCA elevated the activities of antioxidant enzymes including peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD). Transcriptome analysis identified 743 differentially expressed genes (DEGs, 505 up-regulated and 238 down-regulated) in response to NATCA. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed significant enrichment in phenylpropanoid biosynthesis (taes00940), starch and sucrose metabolism (taes00500), plant hormone signal transduction (taes04075), and biosynthesis of secondary metabolites. Notably, 49 DEGs (47 up, 2 down) were associated with phenylpropanoid biosynthesis, suggesting its potential involvement in NATCA-induced growth responses. Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) validated the expression patterns of seven selected DEGs. Collectively, these findings indicate that NATCA treatment associates with extensive transcriptional reprogramming and enhanced physiological performance in wheat seedlings. The observed enrichment of phenylpropanoid-related genes may contribute to growth promotion and biomass accumulation, although further biochemical and functional studies are required to establish causal relationships. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at https://doi.org/10.1007/s12298-026-01799-z.