Enhanced Long-Term Corrosion Resistance of 316L Stainless Steel by Multilayer Amorphous Carbon Coatings.

Diamond-like carbon (DLC) coatings are effective in protecting the key components of marine equipment and can greatly improve their short-term performance (1.5~4.5 h). However, the lack of investigation into their long-term (more than 200 h) performance cannot meet the service life requirements of marine equipment. Here, three multilayered DLC coatings, namely Ti/DLC, TiCx/DLC, and Ti-TiCx/DLC, were prepared, and their long-term corrosion resistance was investigated. Results showed that the corrosion current density of all DLC coatings was reduced by 1-2 orders of magnitude compared with bare 316L stainless steel (316Lss). Moreover, under long-term (63 days) immersion in a 3.5 wt.% NaCl solution, all DLC coatings could provide excellent long-term corrosion protection for 316Lss, and Ti-TiCx/DLC depicted the best corrosion resistance; the polarization resistances remained at ~3.0 × 107 Ω·cm2 after immersion for 63 days, with more interfaces to hinder the penetration of the corrosive media. Meanwhile, during neutral salt spray (3000 h), the corrosion resistance of Ti/DLC and TiCx/DLC coatings showed a certain degree of improvement because the insoluble corrosion products at the defects blocked the subsequent corrosion. This study can provide a route to designing amorphous carbon protective coatings for long-term marine applications in different environments.

Analysis of endophytic bacterial diversity in seeds of different genotypes of cotton and the suppression of Verticillium wilt pathogen infection by a synthetic microbial community.

BACKGROUND: In agricultural production, fungal diseases significantly impact the yield and quality of cotton (Gossypium spp.) with Verticillium wilt posing a particularly severe threat. RESULTS: This study is focused on investigating the effectiveness of endophytic microbial communities present in the seeds of disease-resistant cotton genotypes in the control of cotton Verticillium wilt. The technique of 16S ribosomal RNA (16S rRNA) amplicon sequencing identified a significant enrichment of the Bacillus genus in the resistant genotype Xinluzao 78, which differed from the endophytic bacterial community structure in the susceptible genotype Xinluzao 63. Specific enriched strains were isolated and screened from the seeds of Xinluzao 78 to further explore the biological functions of seed endophytes. A synthetic microbial community (SynCom) was constructed using the broken-rod model, and seeds of the susceptible genotype Xinluzao 63 in this community that had been soaked with the SynCom were found to significantly control the occurrence of Verticillium wilt and regulate the growth of cotton plants. Antibiotic screening techniques were used to preliminarily identify the colonization of strains in the community. These techniques revealed that the strains can colonize plant tissues and occupy ecological niches in cotton tissues through a priority effect, which prevents infection by pathogens. CONCLUSION: This study highlights the key role of seed endophytes in driving plant disease defense and provides a theoretical basis for the future application of SynComs in agriculture.

Concerning the stability of seawater electrolysis: a corrosion mechanism study of halide on Ni-based anode.

The corrosive anions (e.g., Cl-) have been recognized as the origins to cause severe corrosion of anode during seawater electrolysis, while in experiments it is found that natural seawater (~0.41 M Cl-) is usually more corrosive than simulated seawater (~0.5 M Cl-). Here we elucidate that besides Cl-, Br- in seawater is even more harmful to Ni-based anodes because of the inferior corrosion resistance and faster corrosion kinetics in bromide than in chloride. Experimental and simulated results reveal that Cl- corrodes locally to form narrow-deep pits while Br- etches extensively to generate shallow-wide pits, which can be attributed to the fast diffusion kinetics of Cl- and the lower reaction energy of Br- in the passivation layer. Additionally, for the Ni-based electrodes with catalysts (e.g., NiFe-LDH) loading on the surface, Br- causes extensive spalling of the catalyst layer, resulting in rapid performance degradation. This work clearly points out that, in addition to anti-Cl- corrosion, designing anti-Br- corrosion anodes is even more crucial for future application of seawater electrolysis.

Host insect specificity and interspecific competition drive parasitoid diversification in a plant-insect community.

Ecological interactions among plants, insect herbivores, and parasitoids are pervasive in nature and play important roles in community assembling, but the codiversification of tri-trophic interactions has received less attention. Here we compare pairwise codiversification patterns between a set of 22 fig species, their herbivorous pollinating and galling wasps, and their parasitoids. The parasitoid phylogeny showed significant congruence and more cospeciation events with host insects phylogeny than with host plants. These results suggest that parasitoid phylogeny and speciation is more closely related to their host insects than to their host plants. The pollinating wasps hosted more parasitoid species than gallers and indicated a more intense interspecific competition among parasitoids associated with pollinators. Closer matching and fewer evolutionary host shifts were found between parasitoids and galler hosts than between parasitoids and pollinator hosts. These results suggest that interspecific competition among parasitoids, rather than resource availability of host wasps, is the main driver of the codiversification pattern in this community. Therefore, our study highlights the important role of interspecific competition among high trophic level insects in plant-insect tri-trophic community assembling.

Tumor necrosis factor-α upregulates polymeric immunoglobulin receptor expression by NF-κB signaling pathways in grass carp (Ctenopharyngodon idellus) liver cells.

The polymeric immunoglobulin receptor (pIgR) is essential for controlling polymeric immunoglobulin to defend species from invading pathogens. However, the modulation pathway of pIgR expression in teleosts remains unclear. In this paper, to define that the cytokine TNF-α impacted the expression of pIgR, the recombinant proteins of TNF-α of grass carp were first prepared after approving that natural pIgR was expressed in liver cells of grass carp (Ctenopharyngodon idellus) (L8824). L8824 cells were incubated with variable amounts of recombinant TNF-α at various times, the results revealed that pIgR expressions showed a significant dose-dependent elevation at the gene and proteins, and a similar alteration trend was detected for the pIgR protein (secretory component: SC) secreted by L8824 cells into the culture supernatant. Moreover, nuclear factor kappa-B (NF-κB) inhibitors PDTC was used to study whether TNF-α regulated pIgR expressions through the NF-κB signaling pathways. L8824 cells were treated with TNF-α, inhibitor PDTC, and TNF-α + PDTC mixtures, respectively, and the levels of pIgR genes and pIgR protein in cells and SC in the culture supernatant decreased in cells treated with PDTC contrasted to the control, and subjected to reduced expression of PDTC + TNF-α reduced expression contrasted to that treated just with TNF-α, demonstrating that suppression of NF-κB obstructed the ability of TNF-α to elevate pIgR gene and pIgR protein in cells and SC in the culture supernatant. These outcomes indicated that TNF-α raised pIgR gene expression, pIgR protein, and SC creation, and this pIgR expression induced by TNF-α was modulated by complicated pathways that included NF-κB signaling mechanism, confirming TNF-α as a pIgR expression modulator and enhancing a deeper insight of the regulatory pathway for pIgR expression in teleosts.

The Role of Reactive Oxygen Species in Plant Response to Radiation.

Radiation is widespread in nature, including ultraviolet radiation from the sun, cosmic radiation and radiation emitted by natural radionuclides. Over the years, the increasing industrialization of human beings has brought about more radiation, such as enhanced UV-B radiation due to ground ozone decay, and the emission and contamination of nuclear waste due to the increasing nuclear power plants and radioactive material industry. With additional radiation reaching plants, both negative effects including damage to cell membranes, reduction of photosynthetic rate and premature aging and benefits such as growth promotion and stress resistance enhancement have been observed. ROS (Reactive oxygen species) are reactive oxidants in plant cells, including hydrogen peroxide (H2O2), superoxide anions (O2•-) and hydroxide anion radicals (·OH), which may stimulate the antioxidant system of plants and act as signaling molecules to regulate downstream reactions. A number of studies have observed the change of ROS in plant cells under radiation, and new technology such as RNA-seq has molecularly revealed the regulation of radiative biological effects by ROS. This review summarized recent progress on the role of ROS in plant response to radiations including UV, ion beam and plasma, and may help to reveal the mechanisms of plant responses to radiation.

Collection, nucleic acid release, amplification, and visualization platform for rapid field detection of rice false smut.

Rice false smut (RFS) has brought serious food safety problems to the world. Reliable diagnostic tools are needed for the field detection of RFS. Traditional polymerase chain reaction (PCR) is inefficient due to sample transport and preparation, which cannot adapt to the needs of field detection. Herein, we successfully developed a simple, portable microfluidic test platform to rapidly detect RFS. To simplify the operation, we integrated spore purification, nucleic acid release, and amplification into one chip. A micro air pump was used to separate the spores from the impurities and complete the collection of the spores through the airflow. We rapidly lysed spores and released nucleic acids by the benzyl chloride method. The loop-mediated isothermal amplification (LAMP) products could be combined with SYBR Green I to observe the results visually. On-chip sample tests showed that the spore collection efficiency was approximately 78%. By providing on-chip detection results, the chip had 100% specificity and a detection limit of 100 copies/reaction. At the same time, the stability (CV < 5%) and quantitative ability (R2 = 0.989) of the chip were also guaranteed. Through the visual detection of large samples, the on-chip detection results were highly concordant with the classical RT-PCR detection results, and the detection timeliness was greatly enhanced. Compared with RT-PCR, the single-sample detection time was shortened by about twenty minutes. The proposed micro-diagnostic tool did not require any large end-point detection instruments and avoided the complicated operation of nucleic acid extraction. As a result, in the future, our microfluidic chip could be used for rapid and real-time monitoring and early warning of rice false smut spores in rice paddies.

Vertical transfer and functional characterization of cotton seed core microbiome.

Introduction: Microbiome within plant tissues is pivotal for co-evolution with host plants. This microbiome can colonize the plant, with potential transmission via seeds between parents and offspring, affecting seedling growth and host plant adaptability to the environment. Methods: We employed 16S rRNA gene amplicon analysis to investigate the vertical distribution of core microbiome in cotton seeds across ecological niches [rhizosphere, root, stem, leaf, seed and seed-P (parental seed)] of the three cotton genotypes. Results: The findings demonstrated a significant decrease in microbiome diversity and network complexity from roots, stems, and leaves to seeds. The microenvironment exerted a more substantial influence on the microbiome structure of cotton than the genotypes. The core endophytic microorganisms in cotton seeds comprised 29 amplicon sequence variants (ASVs) affiliated with Acidimicrobiia, Alphaproteobacteria, Bacilli, Bacteroidia, Clostridia, Gammaproteobacteria, and unclassified_Proteobacteria. These vertically transmitted taxa are widely distributed in cotton plants. Through 16S rRNA gene-based function prediction analysis of the cotton microbiome, we preliminarily understood that there are potential differences in metabolic capabilities and phenotypic traits among microbiomes in different microhabitats. Discussion: In conclusion, this study demonstrated the crucial role of the microenvironment in influencing the cotton microbiome and offered insights into the structures and functions of the cotton seed microbiome, facilitating future crop yield enhancement through core seed microbiome regulation.

Correction: An integrated nucleic acid detection method based on a microfluidic chip for collection and culture of rice false smut spores.

Correction for 'An integrated nucleic acid detection method based on a microfluidic chip for collection and culture of rice false smut spores' by Ning Yang et al., Lab Chip, 2022, https://doi.org/10.1039/d2lc00931e.

An integrated nucleic acid detection method based on a microfluidic chip for collection and culture of rice false smut spores.

Rice false smut spores (RFSS), which are airborne spores caused by Ustilaginoidea virens (U. virens), not only cause severe yield loss and grain quality reduction, but also produce toxins that are harmful to humans and animals. Nucleic acid detection has become the main method for RFSS monitoring due to its high specificity and sensitivity. However, nucleic acid detection requires multiple steps of spore collection, DNA extraction, nucleic acid amplification and detection, which has a high demand for personnel and is hard to link with other intelligent equipment to achieve automation. Microfluidic chip has become an important approach for integrated detection of pathogens owning to miniaturization and integration in recent years. Yet there is a lack of portable methods that integrate the collection of airborne fungal spores and nucleic acid detection. Because RFSS have thick cell walls and require liquid nitrogen grinding to extract DNA, breaking the walls on-chip is difficult. Therefore, the realization of RFSS wall breaking on-chip is a major difficulty and also a very meaningful study. This study uses RFSS as the research object and provides a novel method of culturing RFSS on-chip to solve the problem of hard wall breaking, realizing the integrated detection of RFSS. The mycelium grown by RFSS germination could be easily broken to release DNA for on-chip detection, which eliminates the need for manual DNA extraction and resolves the issue of difficult wall breaking. This chip can collect RFSS based on the aerodynamic theory and achieve gas-liquid coupling through a simple microvalve structure. A micromixer is constructed to mix the liquid, and then accomplish detection quickly by recombinase polymerase amplification and lateral flow dipsticks (RPA-LFD). The detection sensitivity of this method is 1 × 102-1 × 105 CFU ml-1. It can realize the "sample in and answer out" detection of RFSS due to its simple operation, independence from precision instruments, high sensitivity and specificity. The result shows that it can be used for the early detection of RFSS, has great application prospects and is expected to promote the development of on-site instant detection equipment.

[Hydraulics and non-structural carbohydrate contents of Ginkgo biloba under different environmental conditions in Shenyang City, China.] / 沈阳市区不同环境下银杏水力特征和非结构性碳水化合物含量.

Ginkgo biloba is an important urban ornamental tree species, but poor growth and damages often occur in urban environments. As a street tree species, the decline and death of G. biloba is particularly frequent, with the relevant physiological mechanism being unclear. In this study, we compared hydraulic characteristics, non-structural carbohydrate (NSC) contents and health status between G. biloba trees growing along the streets and those in parks in Shenyang City. The results showed that G. biloba growing along the streets showed higher degrees of branch and leaf mortality than those growing in the parks. Branches of G. biloba growing in both conditions showed lower degrees of xylem embolism. Branch hydraulic vulnerable curves of G. biloba under the two growing conditions also showed no significant difference, with the average P50 being lower than -2.8 MPa. G. biloba growing along the streets had lower leaf area specific conductivity, smaller tracheid diameter, smaller hydraulic diameter, lower soluble sugar content and total NSC than those growing in parks. Hydraulic failure was not the direct reason for the decline and mortality of G. biloba growing along streets. Under the more stressed growth conditions along the streets, G. biloba had smaller tracheid diameters in stems and lower Huber values, which limited the ability of water transport and photosynthetic carbon assimilation at the whole branch level. In addition, in order to deal with more serious stress such as greater heat and drought stresses, G. biloba might need to invest more NSC to repair damage, which further decreaded NSC contents in branches and increased the risk of carbon imbalance. At the same habitat (street or park), xylem hydraulics and NSC contents of G. biloba also showed relatively large difference among sampling sites, which reflected large heterogeneity of urban environment for tree growth.

High-throughput sequencing reveals soil bacterial community structure and their interactions with environmental factors of the grassland fairy ring.

Fairy rings (FRs) are common ecological grassland landscapes that have been studied for a long time. However, little is known about their interactions with soil physicochemical properties and bacterial communities. This study performed high-throughput sequencing of the 16S rRNA V3-V4 variable regions of soil bacteria in the three concentric zones of chosen FR, namely, the ON zone, on the ring; IN zone, inside the ring; and OUT zone, outside the ring. Also, the change in physicochemical properties and enzyme activities of the soil were determined. This study found that the nutrients and enzyme activities on the ring were higher than inside and outside of the ring. The activities of microorganisms were frequent and the plant grew splendidly. The bacterial species diversity was the lowest on the ring with the main genera Pseudonocardia, Streptosporangium, Kribbella and Promicromonospora. The imbalance of the microbial community structure at different ring zones may be the driving factor for the continuous outward expansion of FRs. Soil available phosphorus, electrical conductivity, total nitrogen and organic matter positively correlated with the distribution of FR soil bacteria.

Habitat effects on reproductive phenotype, pollinator behavior, fecundity, and mating outcomes of a bumble bee-pollinated herb.

PREMISE: Fecundity and mating outcomes commonly differ among plant populations occupying contrasting environments. If self-pollination occurs primarily among flowers within plants, contrasting reproductive outcomes among populations must reflect environmental effects on plant-pollinator interactions. Specifically, local conditions could affect features of plant phenotypes that influence pollinator behavior, in turn modifying plant reproductive outcomes. METHODS: We compared phenotypes, pollinator abundance and behavior, and female fecundity and mating in two meadow populations and two forest populations of Aconitum kusnezoffii within 3 km of each other. Mating outcomes were assessed using microsatellites. RESULTS: Meadow plants generally produced more, shorter ramets with more, larger flowers, but less nectar per flower than forest plants. These differences likely largely represent phenotypic plasticity. Individual bumble bees visited more flowers on forest plants, likely because the more abundant bees in the meadows depleted nectar availability, as indicated by briefer visits to individual flowers. Despite similar fruit set in both habitats, forest plants set more seeds per fruit. Nevertheless, meadow plants produced more seeds overall, owing to sevenfold greater flower production. Consistent with individual bees visiting fewer flowers on meadow plants, more of their seeds were outcrossed. However, the outcrossed seeds of forest plants included more male mates. CONCLUSIONS: Reproductive outcomes can vary among populations of animal-pollinated plants as a result of differences in the availability of effective pollinators and environmental effects on plant phenotypes, and their functional consequences for pollinator behavior that governs pollen dispersal.

Discovery of a Partial Glucokinase Activator Clinical Candidate: Diethyl ((3-(3-((5-(Azetidine-1-carbonyl)pyrazin-2-yl)oxy)-5-isopropoxybenzamido)-1H-pyrazol-1-yl)methyl)phosphonate (BMS-820132).

Glucokinase (GK) is a key regulator of glucose homeostasis, and its small-molecule activators represent a promising opportunity for the treatment of type 2 diabetes. Several GK activators have been advanced into clinical trials and have demonstrated promising efficacy; however, hypoglycemia represents a key risk for this mechanism. In an effort to mitigate this hypoglycemia risk while maintaining the efficacy of the GK mechanism, we have investigated a series of amino heteroaryl phosphonate benzamides as ''partial" GK activators. The structure-activity relationship studies starting from a "full GK activator" 11, which culminated in the discovery of the "partial GK activator" 31 (BMS-820132), are discussed. The synthesis and in vitro and in vivo preclinical pharmacology profiles of 31 and its pharmacokinetics (PK) are described. Based on its promising in vivo efficacy and preclinical ADME and safety profiles, 31 was advanced into human clinical trials.

Genome-Wide Characterization and Expression Analysis Provide Basis to the Biological Function of Cotton FBA Genes.

Fructose-1,6-biphosphate aldolase (FBA) is a multifunctional enzyme in plants, which participates in the process of Calvin-Benson cycle, glycolysis and gluconeogenesis. Despite the importance of FBA genes in regulating plant growth, development and abiotic stress responses, little is known about their roles in cotton. In the present study, we performed a genome-wide identification and characterization of FBAs in Gossypium hirsutum. Totally seventeen GhFBA genes were identified. According to the analysis of functional domain, phylogenetic relationship, and gene structure, GhFBA genes were classified into two subgroups. Furthermore, nine GhFBAs were predicted to be in chloroplast and eight were located in cytoplasm. Moreover, the promoter prediction showed a variety of abiotic stresses and phytohormone related cis-acting elements exist in the 2k up-stream region of GhFBA. And the evolutionary characteristics of cotton FBA genes were clearly presented by synteny analysis. Moreover, the results of transcriptome and qRT-PCR analysis showed that the expression of GhFBAs were related to the tissue distribution, and further analysis suggested that GhFBAs could respond to various abiotic stress and phytohormonal treatments. Overall, our systematic analysis of GhFBA genes would not only provide a basis for the understanding of the evolution of GhFBAs, but also found a foundation for the further function analysis of GhFBAs to improve cotton yield and environmental adaptability.

Insights into Superlow Friction and Instability of Hydrogenated Amorphous Carbon/Fluid Nanocomposite Interface.

Hydrogenated amorphous carbon (a-C:H) film exhibits the superlubricity phenomena as rubbed against dry sliding contacts. However, its antifriction stability strongly depends on the working environment. By composting with the fluid lubricant, the friction response and fundamental mechanisms governing the low-friction performance and instability of a-C:H remain unclear, while they are not accessible by experiment due to the complicated interfacial structure and the lack of advanced characterization technique in situ. Here, we addressed this puzzle with respect to the physicochemical interactions of a-C:H/oil/graphene nanocomposite interface at atomic scale. Results reveal that although the friction capacity and stability of system are highly sensitive to the hydrogenated degrees of mated a-C:H surfaces, the optimized H contents of mated a-C:H surfaces are suggested in order to reach the superlow friction or even superlubricity. Interfacial structure analysis indicates that the fundamental friction mechanism attributes to the hydrogenation-induced passivation of friction interface and squeezing effect to fluid lubricant. Most importantly, the opposite diffusion of fluid oil molecules to the sliding direction is observed, resulting in the transformation of the real friction interface from a-C:H/oil interface to oil/oil interface. These outcomes enable an effective manipulation of the superlow friction of carbon-based films and the development of customized solid-fluid lubrication systems for applications.

SiFBA5, a cold-responsive factor from Saussurea involucrata promotes cold resilience and biomass increase in transgenic tomato plants under cold stress.

BACKGROUND: Saussurea involucrata survives in extreme arctic conditions and is very cold-resistant. This species grows in rocky, mountainous areas with elevations of 2400-4100 m, which are snow-covered year-round and are subject to freezing temperatures. S. involucrata's ability to survive in an extreme low-temperature environment suggests that it has particularly high photosynthetic efficiency, providing a magnificent model, and rich gene pool, for the analysis of plant cold stress response. Fructose-1, 6-bisphosphate aldolase (FBA) is a key enzyme in the photosynthesis process and also mediates the conversion of fructose 1, 6-bisphosphate (FBP) into dihydroxyacetone phosphate (DHAP) and glycerol triphosphate (GAP) during glycolysis and gluconeogenesis. The molecular mechanisms underlying S. involucrata's cold tolerance are still unclear; therefore, our work aims to investigate the role of FBA in plant cold-stress response. RESULTS: In this study, we identified a cold-responsive gene, SiFBA5, based on a preliminary low-temperature, genome-wide transcriptional profiling of S. involucrata. Expression analysis indicated that cold temperatures rapidly induced transcriptional expression of SiFBA5, suggesting that SiFBA5 participates in the initial stress response. Subcellular localization analysis revealed that SiFBA5 is localized to the chloroplast. Transgenic tomato plants that overexpressed SiFBA5 were generated using a CaMV 35S promoter. Phenotypic observation suggested that the transgenic plants displayed increased cold tolerance and photosynthetic efficiency in comparison with wild-type plants. CONCLUSION: Cold stress has a detrimental impact on crop yield. Our results demonstrated that SiFBA5 positively regulates plant response to cold stress, which is of great significance for increasing crop yield under cold stress conditions.

Cold-regulated gene LeCOR413PM2 confers cold stress tolerance in tomato plants.

Tomato (Lycopersicon esculentum Mill) is an important food plant that has been used as a model plant in genetic evolution and molecular biology research. The plant is originated from the tropics; thus, it is sensitive to cold. Its growth and development can be easily affected by cold stress. In this study, cold-regulated gene LeCOR413PM2 was cloned from tomato leaves and then used to generate two types of transgenic tomato plants: LeCOR413PM2-overexpressing transgenic plants and RNA-interference-expressing transgenic plants. The functions and expression of LeCOR413PM2 gene in response to cold stress were subsequently assessed. The results showed that LeCOR413PM2 localized in the plasma membrane. Expression of LeCOR413PM2 gene in the leaf of transgenic tomato plant was highest compared to that in other organs (i.e., root, stem, flower and fruit); it was elevated when plants were treated with cold stress. Overexpression of LeCOR413PM2 gene was found to not only reduce damage to cell membrane, accumulation of ROS, and photoinhibition of PSII, but also maintain high activity of antioxidant enzymes and content of osmotic regulators. The results also reveal that high activities of antioxidant enzymes were caused by the up-regulation of their gene expressions. This study demonstrates that the overexpression of LeCOR413PM2 could increase cold tolerance of transgenic tomato plants, while the suppressed expression of LeCOR413PM2 by RNA interference could increase the sensitivity of plants to cold.

Ectopic Expression of the Allium cepa 1-SST Gene in Cotton Improves Drought Tolerance and Yield Under Drought Stress in the Field.

In some plants, sucrose: sucrose 1-fructosyltransferase (1-SST) is the first irreversible key enzyme in fructan biosynthesis. Studies have shown that fructan accumulation enhances abiotic stress tolerance of plants. To investigate the role of 1-SST in drought stress responses, a total of 37 cotton plants expressing a 1-SST gene from Allium cepa were developed by Agrobacterium-mediated transformation. Under drought stress in the field, compared with wild-type, ectopic expression of Ac1-SST in cotton resulted in significantly higher soluble sugars (especially 1-kestose), proline and relative water contents, as well as decreased malondialdehyde content, which contributed to maintaining intracellular osmoregulation and reducing membrane damage. In addition, ectopic expression of Ac1-SST in cotton significantly improved the photosynthesis rate, performance of PSII (including Pn, Fv/Fm, WUE, ΦPSII, and PItotal) and plant growth under drought stress. Furthermore, compared with the wild-type, under the droughted field, the yield loss per square meter of transgenic cotton was reduced by an average of 20.9% over two consecutive years. Our results indicate that the Ac1-SST gene can be used to improve drought tolerance and yield of cotton varieties, and might also be a promising drought-resistant gene for improving other crop varieties.

The SikCuZnSOD3 gene improves abiotic stress resistance in transgenic cotton.

The expression of a gene encoding peroxisomal Cu-Zn superoxide dismutase from Saussurea involucrata Kar. et Kir. was induced by low temperature, PEG6000 treatment, and NaCl stress. To investigate the role of SikCuZnSOD3 in the mitigation of abiotic stress, we used Agrobacterium-mediated transformation to create transgenic cotton that overexpressed SikCuZnSOD3. Phenotypic analysis of T4 generation transgenic lines showed that they generally grew better than wild-type cotton under low temperature, PEG6000 treatment, and NaCl stress. Although there were no significant differences under control conditions, transgenic plants exhibited greater survival, fresh weight, and dry weight than wild-type plants under all three stress treatments. Additional physiological analyses demonstrated that the transgenic cotton had higher relative water content, proline and soluble sugar contents, and activity of antioxidant enzymes (superoxide dismutase, catalase, and peroxidase), as well as lower relative conductivity, malondialdehyde content, and H2O2 and O2- accumulation. More importantly, overexpression of SikCuZnSOD3 increased the yield of cotton fiber. Our results confirm that the overexpression of SikCuZnSOD3 can improve the abiotic stress resistance of cotton by increasing the activity of antioxidant enzymes, maintaining ROS homeostasis, and reducing cell membrane damage. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-021-01217-0.