Transcriptional and metabolic responses of apple to different potassium environments

Abstract

Potassium (K) is one of the most important macronutrients for plant development and growth. The influence mechanism of different potassium stresses on the molecular regulation and metabolites of apple remains largely unknown. In this research, physiological, transcriptome, and metabolite analyses were compared under different K conditions in apple seedlings. The results showed that K deficiency and excess conditions influenced apple phenotypic characteristics, soil plant analytical development (SPAD) values, and photosynthesis. Hydrogen peroxide (H2O2) content, peroxidase (POD) activity, catalase (CAT) activity, abscisic acid (ABA) content, and indoleacetic acid (IAA) content were regulated by different K stresses. Transcriptome analysis indicated that there were 2,409 and 778 differentially expressed genes (DEGs) in apple leaves and roots under K deficiency conditions in addition to 1,393 and 1,205 DEGs in apple leaves and roots under potassium excess conditions, respectively. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment showed that the DEGs were involved in flavonoid biosynthesis, photosynthesis, and plant hormone signal transduction metabolite biosynthetic processes in response to different K conditions. There were 527 and 166 differential metabolites (DMAs) in leaves and roots under low-K stress as well as 228 and 150 DMAs in apple leaves and roots under high-K stress, respectively. Apple plants regulate carbon metabolism and the flavonoid pathway to respond to low-K and high-K stresses. This study provides a basis for understanding the metabolic processes underlying different K responses and provides a foundation to improve the utilization efficiency of K in apples.

Exploring the Impact of Potassium on Growth, Photosynthetic Performance, and Nutritional Status of Lemon Trees (cv. Adamopoulou) Grafted onto Sour Orange and Volkamer Lemon Rootstocks

“…Çelik et al [32] documented comparable results in maize, where increased potassium doses positively influenced the dry weight of leaves and roots, except at very high potassium levels combined with high iron supply, which resulted in decreased plant dry weights, especially in leaves. In another study, Sun et al [33] reported negative impacts of both low and high K levels on total plant growth in apple plants. Overall, increased K concentrations have been shown to have varying positive effects on plant growth, depending on the plant species.…”

Comparative physiological and transcriptome analysis between potassium-deficiency tolerant and sensitive sweetpotato genotypes in response to potassium-deficiency stress

“…Transcriptome technology as a convenient tool can rapid distinguishes differentially expressed genes (DEGs) under a variety of environmental conditions. Some important genes encoding kinases, transcription factors, carbohydrates, or involved in the signal transduction pathway including second messenger, reactive oxygen species (ROS), plant hormones during the plants responses to K-deficiency were identified via transcriptomic analyses in many plants, including rice, wheat, apple and banana [17][18][19][20].…”