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The upside-down water collection system of Syntrichia caninervis

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Abstract

Desert plants possess highly evolved water conservation and transport systems, from the root structures that maximize absorption of scarce ground water1, 2, 3, 4, 5, to the minimization of leaf surface area6 to enhance water retention. Recent attention has focused on leaf structures that are adapted to collect water and promote nucleation from humid air7, 8, 9. Syntrichia caninervis Mitt. (Pottiaceae) is one of the most abundant desert mosses in the world and thrives in an extreme environment with multiple but limited water resources (such as dew, fog, snow and rain), yet the mechanisms for water collection and transport have never been completely revealed. S. caninervis has a unique adaptation: it uses a tiny hair (awn) on the end of each leaf to collect water, in addition to that collected by the leaves themselves. Here we show that the unique multiscale structures of the hair are equipped to collect and transport water in four modes: nucleation of water droplets and films on the leaf hair from humid atmospheres; collection of fog droplets on leaf hairs; collection of splash water from raindrops; and transportation of the acquired water to the leaf itself. Fluid nucleation is accomplished in nanostructures, whereas fog droplets are gathered in areas where a high density of small barbs are present and then quickly transported to the leaf at the base of the hair. Our observations reveal nature's optimization of water collection by coupling relevant multiscale physical plant structures with multiscale sources of water.
... Meanwhile, overexpression of PtABI3 acted on appropriate growth and differentiation of embryonic leaves before bud set and dormancy [17], and overexpression of MtA-BI3/MtRAV3 enhanced osmotic and salt tolerance and inhibited the growth of Medicago truncatula [18]. Syntrichia caninervis is a desert moss with extreme desiccation tolerance, rapid rehydration, and photosynthetic recovery, which is widely distributed in the Gurbantunggut Desert of Xinjiang and is considered an excellent material for studying desert plants and a potential source of genes for improving stress tolerance [19]. Previous studies have reported that ScABI3 is localized in the nucleus where it acts as a transcription factor. ...
... S. caninervis is a highly drought-tolerant desert moss that was key in transitioning aquatic to terrestrial plants. It is also a good source of genetic materials for stress tolerance [19]. Therefore, the study used one of its genes with the known function that is an ideal method of promoting the growth and quality of crops. ...
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ABI3 (ABSCISIC ACID INSENSITIVE 3) is a family of B3 transcription factors essential for regulating the abscisic acid (ABA) signaling pathway involved in various biological processes and abiotic stress. Our previous studies demonstrated that ectopic expression of ScABI3 from a desiccation-tolerant moss (Syntrichia caninervis) into Arabidopsis thaliana enhanced abiotic stress tolerance. However, studies on plant transformation using the ABI3 gene are limited and other possible functions of ScABI3 are not known. Here, we transformed the ScABI3 into alfalfa (Medicago sativa L.) and analyzed the effects on phenotype, photosynthetic efficiency, and nutritional quality. The results showed that the endogenous ABA content of the transgenic plants was significantly higher than WT, and the leaf-stem ratio, leaf area, and branch number increased with ScABI3 overexpression in alfalfa. Further analysis of the gas exchange parameters showed that the net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), and water-use efficiency (WUE) of the transgenic alfalfa were significantly higher than WT; meanwhile, the protein content of the transgenic lines was higher than the WT, but the crude fat content was lower. Thus, these findings suggest that ScABI3 can be used as a potential candidate gene to manipulate alfalfa's growth and nutritional quality. This study will provide a theoretical basis for breeding alfalfa varieties and assist in forage production and animal husbandry in the future.
... Our data also confirmed that NRW in biocrusts was substantially higher than that in bare soil mineral specific surface area because of the higher fine particle contents, which therefore provide more surface area for NRW deposition (Chamizo et al., 2021;Kidron et al., 2002); (iii) biocrusts decrease surface albedo and regulate surface soil thermal properties (e.g., heat capacity, thermal conductivity, and thermal diffusivity), resulting in the differences of surface and subsurface temperatures (Li et al., 2022c;Ouyang et al., 2017;Xiao & Bowker, 2020;Xiao et al., 2019a); and (iv) the morphology of some biocrust organisms (e.g., moss stems, leaves and awns, cushions, and the rhizoids) could play an important part in water collectio n, imbibition, transportation, and storage (Pan et al., 2016;Tao & Zhang, 2012). Consequently, the development of biocrusts changes multiple surface soil properties that favor greater capacity to capture and hold NRW. ...
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As a crucial living feature inhabiting the soil‐atmosphere boundary, biocrusts play a vital role in liquid water or vapor transport through surface soil and thus have strong effects on soil water regimes. However, it remains unclear how biocrusts affect annual or multi‐year soil water budgets through the regulation of evaporation outputs and NRW or infiltration inputs. Thus, we used automated microlysimeters to continually investigate the differences in evaporation and NRW rates between moss‐dominated biocrusts and bare soil at 0−5 cm depth for two years. The upper 30 cm of soil moisture (θ) and water storage (W) of bare soil and biocrusts were also monitored. Our results showed that the daily evaporation rate (E) of biocrusts was 17% higher than bare soil. Especially after rainfall events, biocrusts had higher E and larger cumulative evaporation than bare soil. Besides, the daily NRW of biocrusts averaged 15% higher than bare soil over two years. Furthermore, biocrusts increased θ by 11%−76% at 0−10 cm depth but decreased θ by 32%−56% at 20−30 cm depth in comparison to bare soil, and they subsequently decreased W by 20% at 0−30 cm depth. Summarized annually, the NRW amount of biocrusts was 19% higher than bare soil, but at the same time the cumulative evaporation of biocrusts was also 19% higher than bare soil. Finally, biocrusts resulted in more water loss at shallow depth through evaporation and lessened total W throughout 0−30 cm depth of soil. These findings demonstrate that although biocrusts input more NRW into surface soil, these water inputs partially offset their intensified evaporation. Given that all rainfall water infiltrates into the soil in our study system, our findings indicate that biocrusts may have an overall negative effect on soil water balance there, while at the same time increasing water storage and availability of the deeper soil underlying biocrusts.
... Moreover, the established patterns of vascular plants may not necessarily apply to bryophytes (Vanderpoorten and Goffinet, 2009), since the requirement, uptake, allocation, and releasing rate of nutrients are quite different between these two groups: 1) the requirement of nutrients of bryophytes is generally lower than that of vascular plants, in accordance to the former's relatively low growth rates and small sizes (Strengbom and Nordin, 2008). 2) Bryophytes have no true roots and the rhizoids of bryophytes can only penetrate the shallow soil layer with the main function of anchoring the gametophyte to the substrate (Pan et al., 2016). With their relatively simple morphological and anatomical structures, bryophytes can absorb nutrients through their entire surface (Glime, 2017), thus intercepting and absorbing atmospheric elements directly (Huang et al., 2019). ...
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With special phylogenetic status, life history, morphology, adaptations, and ecophysiological strategies, bryophytes differ from vascular plants in terms of the requirement, uptake, allocation, and releasing rate of nutrients. However, biogeographical patterns of nutrients for bryophytes remain largely unknown. The present study determined and calculated the community-level carbon (C), nitrogen (N), and phosphorus (P) content and their stoichiometric ratios of the photosynthetic tissues of the subtropical forest-floor bryophytes collected from 295 sites in Sichuan province, China. We aimed to find out: 1) the geographical patterns in the content of N and P and the stoichiometric ratio of N to P for bryophytes; 2) the effects of environmental factors (climate, soil nutrient content, and stand attributes); and 3) the driving factors. We found that the bryophytes collected from the western plateau had a higher P content and a lower N:P than those from the eastern basin. The bryophytes’ N and P content generally increased with increasing elevations and decreasing mean annual temperature (MAT) and potential evaporation, while the N:P ratio decreased with decreasing elevations. But these patterns were scale-dependent. Nutrient content of bryophytes and those of soil were positively associated. Bryophyte N content was unrelated to mean annual precipitation (MAP) and stand attributes, while P content was negatively related to MAP and shrub and herb cover. Among the environmental factors at play, soil nutrient content and MAT were more important determinants of bryophyte N and P content than MAP and stand attributes. This study contributes to a better understanding of the relationships among environmental factors and bryophyte N and P at a basin-mountain transition zone and provides evidence to quantitatively assess the ecological role of bryophytes in nutrient cycling in the ecosystem.
... To a lesser degree, we also observed a significant enrichment of antibiotic synthesis pathways in samples containing moss as the primary producer. The association of antibiotic synthesis with the presence of moss might also reflect the increased availability of moisture to enable diffusion of antibiotics, as mosses possess morphological features (e.g., leaf and branch architecture, leaf papillae, and leaf hair points) that are specialized for the sequestration, transport, and retention of external water (66,67). We note that the enrichment of antibiotic synthesis pathways in hypoliths compared with biocrusts does not imply biocrusts lack this ability. ...
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Biocrusts serve as a keystone element of desert and dryland ecosystems, stabilizing soils, retaining moisture, and serving as a carbon and nitrogen source in oligotrophic environments. Biocrusts cover approximately 12% of the Earth’s terrestrial surface but are threatened by climate change and anthropogenic disturbance.
... [41] However, because of the limitation of solubility, the WIS electrolyte may crystallize and precipitate with the evaporation of water and the decrease of temperature. [39] Herein, inspired by the desert plants [42,43] such as cactus and syntrichia caninervis absorbing water from fog in the ambient air, we designed a WIS nonalkaline electrolyte based on the coordination interactions of Zn(OTF) 2 and acetamide (C 2 H 5 NO). The double-network gel polymer electrolyte (WIS-PAA/CNF) was prepared by a simple method of UV irradiation polymerization in one step, in which PAA was acted as the host polymer and cellulose nanofibers (CNFs) were used as the reinforcing materials. ...
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The biological soil crusts (BSCs) in the Gurbantunggut Desert, the largest fixed and semi-fixed desert in China, feature moss-dominated BSCs, which play an indispensable role in sand fixation. Syntrichia caninervis Mitt. (S. caninervis) serves as one of the most common species in BSCs in the desert. In this study we examined the morphological structure of S. caninervis from leafy gametophyte to protonema using light and scanning electron microscopy (SEM). We also examined the relationships between the morphological structure of S. caninervis and environmental factors. We found that: (1) this moss species is commonly tufted on the sand surface, and its leaves are folded upwards and twisted around the stem under dry conditions; (2) the cells on both upper and lower leaf surfaces have C-shaped dark papillae, which may reflect sunlight to reduce the damage from high temperature; (3) the leaf costa is excurrent, forming an awn with forked teeth; and (4) the protonema cells are small and thickset with thick cell walls and the cytoplasm is highly concentrated with a small vacuole. In addition, we also found that the protonema cells always form pouches on the tip of the mother cells during the process of cell polarization. Our results suggest that S. caninervis has, through its life cycle, several morphological and structural characteristics to adapt to dry environmental conditions. These morphological features of S. caninervis may also be found in other deserts in the world due to the world-wide distribution of the species.