Physiological and Proteomic Analyses of Different Ecotypes of Reed (Phragmites communis) in Adaption to Natural Drought and Salinity

Abstract

Drought and salinity are the two major abiotic stresses constraining the crop yield worldwide. Both of them trigger cellular dehydration and cause osmotic stress which leads to cytosolic and vacuolar volume reduction. However, whether plants share a similar tolerance mechanism in response to these two stresses under natural conditions has seldom been comparatively reported. There are three different ecotypes of reed within a 5 km2 region in the Badanjilin desert of Northwest China. Taking the typical swamp reed (SR) as a control, we performed a comparative study on the adaption mechanisms of the two terrestrial ecotypes: dune reed (DR) and heavy salt meadow reed (HSMR) by physiological and proteomic approaches coupled with bioinformatic analysis. The results showed that HSMR and DR have evolved C4-like photosynthetic and anatomical characteristics, such as the increased bundle sheath cells (BSCs) and chloroplasts in BSCs, higher density of veins, and lower density and aperture of stomata. In addition, the thylakoid membrane fluidity also plays an important role in their higher drought and salinity tolerance capability. The proteomic results further demonstrated that HSMR and DR facilitated the regulation of proteins associated with photosynthesis and energy metabolism, lipid metabolism, transcription and translation, and stress responses to well-adapt to the drought and salinity conditions. Overall, our results demonstrated that HSMR and DR shaped a similar adaption strategy from the structural and physiological levels to the molecular scale to ensure functionality in a harsh environment.

De novo full-length transcriptome analysis of two ecotypes of Phragmites australis (swamp reed and dune reed) provides new insights into the transcriptomic complexity of dune reed and its long-term adaptation to desert environments

“…Deserts are typically a stressful environment with a combination of multiple ecological factors, including alternating combinations of environmental factors such as intense light, drought, high temperature, intense radiation and dramatic temperature differences. The dune reed, which has its habitat in the desert-oasis transition zone, is highly adaptable to desert environments and is a model plant for studying the long-term adaptation of Gramineae to a combination of stresses in the desert in natural conditions [ 5 , 38 ]. Our previous chloroplast genome study showed that the divergence time of swamp reeds and dune reeds was around 73 Mye [ 39 ].…”

“…Our previous chloroplast genome study showed that the divergence time of swamp reeds and dune reeds was around 73 Mye [ 39 ]. In addition, proteome analysis revealed that net photosynthesis was reduced in dune reeds and that protein content and electron transfer efficiency in photosynthesis-related pathways were significantly downregulated [ 38 , 40 , 41 ].…”

“…In addition, P. australis has a wide ecological range and environmental adaptability, with habitats ranging from swamps and lakes to saline deserts, which is important for studying plant responses to abiotic stresses in natural environments. Different ecotypes of reeds are distributed in the oasis-desert transitional zone of northwest China, among which dune reeds (DR), a desert ecotype, is an ideal material for studying the molecular mechanisms of long-term adaptation of Poaceae plants to desert complex adversities [ 7 ]. Swamp reed clumps or groups are densely distributed in watercourses with high biomass and dense distribution.…”

Zinc finger knuckle genes are associated with tolerance to drought and dehydration in chickpea (Cicer arietinum L.)

“…Additionally, two genes, OsCSP1 and OsCSP2, were upregulated in roots and downregulated in shoots of rice seedlings exposed to dehydration (Chaikam and Karlson, 2008). Ecotypes of the reed, Phragmites communis Trin, a hydrophytic species can adapt well to harsh drought conditions, and proteomics analysis indicated that at least two groups of ZF-CCHC proteins are present during plant adaptation (Li et al, 2021). They include a serine-/arginine-rich protein, similar to wheat described above (Sun et al, 2022), and chloroplastic protein DEAD-box ATP-dependent RNA helicase with homology to rice, Os03t0827700 (Sun et al, 2022), Arabidopsis, and maize (Zea mays L.) (Aceituno et al, 2020).…”