Integrated Transcriptomic and Proteomic Analyses Uncover the Regulatory Mechanisms of Myricaria laxiflora Under Flooding Stress

Abstract

Flooding is one of the major environmental stresses that severely influence plant survival and development. However, the regulatory mechanisms underlying flooding stress remain largely unknown in Myricaria laxiflora, an endangered plant mainly distributed in the flood zone of the Yangtze River, China. In this work, transcriptome and proteome were performed in parallel in roots of M. laxiflora during nine time-points under the flooding and post-flooding recovery treatments. Overall, highly dynamic and stage-specific expression profiles of genes/proteins were observed during flooding and post-flooding recovery treatment. Genes related to auxin, cell wall, calcium signaling, and MAP kinase signaling were greatly down-regulated exclusively at the transcriptomic level during the early stages of flooding. Glycolysis and major CHO metabolism genes, which were regulated at the transcriptomic and/or proteomic levels with low expression correlations, mainly functioned during the late stages of flooding. Genes involved in reactive oxygen species (ROS) scavenging, mitochondrial metabolism, and development were also regulated exclusively at the transcriptomic level, but their expression levels were highly up-regulated upon post-flooding recovery. Moreover, the comprehensive expression profiles of genes/proteins related to redox, hormones, and transcriptional factors were also investigated. Finally, the regulatory networks of M. laxiflora in response to flooding and post-flooding recovery were discussed. The findings deepen our understanding of the molecular mechanisms of flooding stress and shed light on the genes and pathways for the preservation of M. laxiflora and other endangered plants in the flood zone.

De novogenome assembly ofMyricaria laxifloraprovides insights into its molecular mechanisms under flooding stress

“…M.laxiflora is one of the important plant species in the Yangtze River Basin in China, but its growth and development are often subjected to flooding stress, which poses a serious threat to its growth and development [3]. In recent years, with the development of sequencing technology and biotechnology, it is possible to further improve the waterlogging tolerance of M.laxiflora [2]. In this study, we assembled a high-quality reference genome for the first time, with a genome size of 1.29 Gb.…”

“…M. laxiflora is a flood tolerant plant that sleeps in summer and autumn, reproduces in winter and spring, and grows on gravel beaches in the Yangtze River water level rise and fall zone [3,4]. During the flood season of the Yangtze River every year, the M. laxiflora hibernate underwater, and when it reaches the dry season, they begin to rapidly grow and reproduce [2]. The construction of the Three Gorges Dam (TGD) has seriously threatened the native habitat environment of M. laxiflora [5].…”

“…Myricaria laxiflora (Tamaricaceae, 2n=24) is a perennial deciduous shrub belonging to the family Tamaricaceae [1,2]. It is a typical rare plant in the riparian zone, mainly distributed in the middle and upper reaches of the Yangtze River in China [1].…”

“…M. laxiflora can be an ideal plant for studying the molecular mechanism of plant flooding tolerance [6,7]. In recent years, many studies have been conducted to investigate the effects of flooding stress on the physiological response of M. laxiflora [2,8,9]. However, little is known about the molecular mechanism of waterlogging tolerance in M. laxiflora , partly due to a lack of high-quality reference genome.…”

Transcriptome Analysis Reveals Genes Associated with Flooding Tolerance in Mulberry Plants

“…In the present study, the expression levels of an APX-encoding gene (21409302), three genes related to GSTU, and one gene coding for SPDS were significantly elevated after submergence. Interestingly, one study showed that the expression of the sAPX gene from Myricaria laxiora is significantly inhibited by flooding stress but is upregulated at the post-flooding recovery stage [ 46 ]. Together, our results indicate that genes related to ROS signaling may play an important role in the flooding stress response of mulberry ( Figure 8 ).…”