Combined Transcriptome and Proteome Analysis to Elucidate Salt Tolerance Strategies of the Halophyte Panicum antidotale Retz

Abstract

Panicum antidotale, a C4 monocot, has the potential to reclaim saline and drylands and to be utilized as fodder and forage. Its adaptability to survive saline stress has been proven with eco-physiological and biochemical studies. However, little is known about its molecular mechanisms of salt tolerance. In this study, an integrated transcriptome and proteome analysis approach, based on RNA sequencing and liquid chromatography tandem mass spectrometry (LC-MS/MS), was used to identify the said mechanisms. Plants were treated with control (0 mM), low (100 mM), and high (300 mM) sodium chloride (NaCl) treatments to distinguish beneficial and toxic pathways influencing plant biomass. The results indicated differential expression of 3,179 (1,126 upregulated/2,053 downregulated) and 2,172 (898 upregulated/1,274 downregulated) genes (DEGs), and 514 (269 upregulated/245 downregulated) and 836 (494 upregulated/392 downregulated) proteins (DEPs) at 100 and 300 mM NaCl, respectively. Among these, most upregulated genes and proteins were involved in salt resistance strategies such as proline biosynthesis, the antioxidant defense system, ion homeostasis, and sugar accumulation at low salinity levels. On the other hand, the expression of several genes and proteins involved in the respiratory process were downregulated, indicating the inability of plants to meet their energy demands at high salinity levels. Moreover, the impairments in photosynthesis were also evident with the reduced expression of genes regulating the structure of photosystems and increased expression of abscisic acid (ABA) mediated pathways which limits stomatal gas exchange. Similarly, the disturbance in fatty acid metabolism and activation of essential ion transport blockers damaged the integrity of the cell membrane, which was also evident with enhanced malondialdehyde (MDA). Overall, the analysis of pathways revealed that the plant optimal performance at low salinity was related to enhanced metabolism, antioxidative defense, cell growth, and signaling pathways, whereas high salinity inhibited biomass accumulation by altered expression of numerous genes involved in carbon metabolism, signaling, transcription, and translation. The data provided the first global analysis of the mechanisms imparting salt stress tolerance of any halophyte at transcriptome and proteome levels.

Salinity and exogenous H2O2 improve gas exchange, osmoregulation, and antioxidant metabolism in quinoa under drought stress

“…Similarly, the quinoa plant exhibited markedly increased proline, TSS, and GB contents under drought stress (Figure 4). However, in saline conditions, plants uptake inorganic ions, especially Na + , in large amounts to achieve osmotic adjustment (Hussain et al, 2023;Sun et al, 2020).…”

“…However, plants grown under combined stress showed higher antioxidant enzymes' activity than plants grown under single drought and salinity (Figure 5). Recently, some studies reported that accumulation of osmolytes, (ROS)-scavenging enzymes, antioxidant system and phytohormones (ABA) production was more pronounced in combined stress conditions (i.e., drought and salinity) than in individual stress in different plants including quinoa (Abbas et al, 2023;dos Santos et al, 2022;Hussain et al, 2020Hussain et al, , 2023Zhang et al, 2017). In this study, a more strenuous antioxidant system might be plausible due to the efficient uptake of inorganic ions as osmotic adjustment (Table 4), which saves energy and eventually results in increased antioxidant (SOD, POD, and CA) activity under combined drought and salt stress (Figure 5).…”

The combination of salt and drought benefits selective ion absorption and nutrient use efficiency of halophyte Panicum antidotale

“…Extensively distributed along with the marginal lands of Pakistan, this C4 perennial grass is utilized as a typical fodder. Detailed investigations have been conducted to characterize the physiological, molecular, and biochemical markers of salt tolerance in this fodder grass (Hussain et al, 2015;Hussain et al, 2021). Our previous work distinguished single and combined effects of drought and salinity stress on the gas exchange properties of this grass (Hussain et al, 2020).…”

Transcriptomic and Proteomic Analyses of Celery Cytoplasmic Male Sterile Line and Its Maintainer Line

“…RNA-seq and iTRAQ analysis of aphids before and after CMV (cucumber mosaic virus) infection identified 20,550 DEGs, however, only 744 DEPs were obtained [ 71 ]. In the study of salt tolerance of Panicum antidotale, 3179 DEGs were detected by RNA-seq at the salt concentration of 100 mM, while only 514 DEPs were identified by Liquid Chromatography Tandem Mass Spectrometer (LC-MS/MS) in the same environment [ 72 ]. In the conjoint analysis of the transcriptomic and proteomic data in this study, gene expression level is often not consistent with its protein accumulation level.…”