Molecular mechanism of mulberry response to drought stress revealed by complementary transcriptomic and iTRAQ analyses

Abstract

Background The use of mulberry leaves has long been limited to raising silkworms, but with the continuous improvement of mulberry (Morus alba) resource development and utilization, various mulberry leaf extension products have emerged. However, the fresh leaves of mulberry trees have a specific window of time for picking and are susceptible to adverse factors, such as drought stress. Therefore, exploring the molecular mechanism by which mulberry trees resist drought stress and clarifying the regulatory network of the mulberry drought response is the focus of the current work. Results In this study, natural and drought-treated mulberry grafted seedlings were used for transcriptomic and proteomic analyses (CK vs. DS9), aiming to clarify the molecular mechanism of the mulberry drought stress response. Through transcriptome and proteome sequencing, we identified 9889 DEGs and 1893 DEPs enriched in stress-responsive GO functional categories, such as signal transducer activity, antioxidant activity, and transcription regulator activity. KEGG enrichment analysis showed that a large number of codifferentially expressed genes were enriched in flavonoid biosynthesis pathways, hormone signalling pathways, lignin metabolism and other pathways. Through subsequent cooperation analysis, we identified 818 codifferentially expressed genes in the CK vs. DS9 comparison group, including peroxidase (POD), superoxide dismutase (SOD), aldehyde dehydrogenase (ALDHs), glutathione s-transferase (GST) and other genes closely related to the stress response. In addition, we determined that the mulberry gene MaWRKYIII8 (XP_010104968.1) underwent drought- and abscisic acid (ABA)-induced expression, indicating that it may play an important role in the mulberry response to drought stress. Conclusions Our research shows that mulberry can activate proline and ABA biosynthesis pathways and produce a large amount of proline and ABA, which improves the drought resistance of mulberry. MaWRKYIII8 was up-regulated and induced by drought and exogenous ABA, indicating that MaWRKYIII8 may be involved in the mulberry response to drought stress. These studies will help us to analyse the molecular mechanism underlying mulberry drought tolerance and provide important gene information and a theoretical basis for improving mulberry drought tolerance through molecular breeding in the future.

Mining and functional characterization of NADPH-cytochrome P450 reductases of the DNJ biosynthetic pathway in mulberry leaves

“…In this study, our findings reveal that, MaCPR2 possesses an electron transfer function, which is crucial for hydroxylases within the biosynthetic pathway of secondary metabolites in mulberry leaves. It provides additional substantiation that the intricate secondary metabolites in mulberry leaves serve as elaborate defense mechanisms, evolving to adapt and ensure survival amidst biotic, or abiotic stress, during the evolutionary process [42]. The biological functions of this gene in response to various stresses in mulberry leaves will be further explored.…”

Genomic approaches to ensure a more sustainable and productive future of mulberry for sericulture industry

“…Nevertheless, a large number of EST experiments have been carried out recently, producing a wealth of data for the study of functional genomics. By examining and sequencing ESTs taken from mature mulberry leaves, researchers are able to start the process of mulberry transcriptomics (Li et al, 2022) [32] .…”

Gut Microbiota Analysis in Silkworms (Bombyx mori) Provides Insights into Identifying Key Bacterials for Inclusion in Artificial Diet Formulations

“…As monophagous insects, silkworms (Bombyx mori) predominantly consume mulberry leaves (Morus alba) in their natural habitat, which are crucial for their nutritional intake [4,8]. The nutrient composition of mulberry leaves, particularly the balance of proteins, carbohydrates, and essential micronutrients, plays a pivotal role in the growth, development, and silk production of silkworms [4,8,9]. However, the increasing demand for silk and the need for cost-effective and efficient production methods have led to the widespread adoption of artificial diets in commercial sericulture [6,[10][11][12].…”