Project description:To study the alteration pattern and defensive response mechanism triggered by herbivorous feeding stimuli under natural conditions, we built a biological model of the interrelationship between the Chinese pine (Pinus tabuliformis Carr.) and the Chinese pine caterpillar (Dendrolimus tabulaeformis Tsai et Liu) within their native habitat. We integrated proteomic and phosphoproteomic data, normalized the results, and combined them with bioinformatics to evaluate and analyze variations in phosphoproteomics in pine needles' response to the caterpillar's feeding stimulus. We systematically identified differentially significant phosphorylated proteins implicated in the pine's defense mechanism against caterpillar stress. Furthermore, we predicted upstream kinases of phosphorylation sites and their activities. Similarly, through an analysis of the Motif patterns of phosphorylated proteins, Mfuzz clustering of phosphorylation sites, kinase regulatory networks and functional modules of phosphorylated protein interaction networks in response to stress within pine, we can investigate the mechanisms behind resistance formation and regulation of caterpillar feeding incentives in pine. The identification results of partially phosphorylated proteins were additionally confirmed through PRM technology. Furthermore, genes upstream of differentially expressed proteins were validated through RT-qPCR detection.
Project description:In plants, ultraviolet (UV)-light is an important driver for their growth and natural distribution and is also a valuable tool for manipulating their productivity as well as their biotic interactions. Understanding plant responses to different UV radiation is sparse, especially from a systems biology perspective and particularly for conifers. Here, we evaluated the physiological and transcriptomic responses to the short-term application of high-irradiance UV-B and UV-C waves on Pinus tabuliformis Carr., a major conifer in Northern China. By undertaking time-ordered gene co-expression network analyses and network comparisons incorporating physiological traits and gene expression variation, we uncovered communalities but also differences in P. tabuliformis responses to UV-B and UV-C. Both types of spectral bands caused a significant inhibition of photosynthesis and conversely improvement of antioxidant capacity, flavonoid production and signaling pathways related to stress resistance, indicating a clear switch from predominantly primary metabolism to enhanced defensive metabolism in pine. We isolated distinct subnetworks for photoreceptor-mediated signal transduction, maximum quantum efficiency of photosystem II (Fv/Fm) regulation and flavonoid biosynthesis in response to UV-B and UV-C irradiation. From these subnetworks, we further identified phototropins as potential important elements in both UV-B and UV-C signaling and, for the first time, reveal peptide hormones possibly involved in promoting flavonoid biosynthesis against UV-B, while these hormones seem not to be implicated in defense against UV-C exposure. The present study employed an effective strategy for disentangling the complex physiological and genetic regulatory mechanisms in a non-model plant species, and thus, provides a suitable reference for future functional evaluations and artificial UV-light mediated growing strategies in plant production.