•A consistent relation between forest cover loss and water is valid across spatial scales.•Scale effect on forest-water relation is significant in large watersheds.•Water-limited watersheds are more ...sensitive to forest change.•Mixed forest dominated small watersheds are more hydrologically resilient to forest change.•Snow dominated large watersheds are more hydrologically resilient to forest change.
Despite extensive studies on hydrological responses to forest cover change in small watersheds, the hydrological responses to forest change and associated mechanisms across multiple spatial scales have not been fully understood. This review thus examined about 312 watersheds worldwide to provide a generalized framework to evaluate hydrological responses to forest cover change and to identify the contribution of spatial scale, climate, forest type and hydrological regime in determining the intensity of forest change related hydrological responses in small (<1000km2) and large watersheds (⩾1000km2). Key findings include: (1) the increase in annual runoff associated with forest cover loss is statistically significant at multiple spatial scales whereas the effect of forest cover gain is statistically inconsistent; (2) the sensitivity of annual runoff to forest cover change tends to attenuate as watershed size increases only in large watersheds; (3) annual runoff is more sensitive to forest cover change in water-limited watersheds than in energy-limited watersheds across all spatial scales; and (4) small mixed forest-dominated watersheds or large snow-dominated watersheds are more hydrologically resilient to forest cover change. These findings improve the understanding of hydrological response to forest cover change at different spatial scales and provide a scientific underpinning to future watershed management in the context of climate change and increasing anthropogenic disturbances.
The Brassica genus encompasses three diploid and three allopolyploid genomes, but a clear understanding of the evolution of agriculturally important traits via polyploidy is lacking. We assembled an ...allopolyploid Brassica juncea genome by shotgun and single-molecule reads integrated to genomic and genetic maps. We discovered that the A subgenomes of B. juncea and Brassica napus each had independent origins. Results suggested that A subgenomes of B. juncea were of monophyletic origin and evolved into vegetable-use and oil-use subvarieties. Homoeolog expression dominance occurs between subgenomes of allopolyploid B. juncea, in which differentially expressed genes display more selection potential than neutral genes. Homoeolog expression dominance in B. juncea has facilitated selection of glucosinolate and lipid metabolism genes in subvarieties used as vegetables and for oil production. These homoeolog expression dominance relationships among Brassicaceae genomes have contributed to selection response, predicting the directional effects of selection in a polyploid crop genome.
•Forest disturbance increased annual streamflow, baseflow, and surface runoff.•Climate variability decreased annual streamflow, baseflow, and surface runoff.•Effects of climate variability on flow ...components were higher than forest change.
Assessing how forest disturbance and climate variability affect streamflow components is critical for watershed management, ecosystem protection, and engineering design. Previous studies have mainly evaluated the effects of forest disturbance on total streamflow, rarely with attention given to its components (e.g., base flow and surface runoff), particularly in large watersheds (>1000 km2). In this study, the Upper Similkameen River watershed (1810 km2), an international watershed situated between Canada and the USA, was selected to examine how forest disturbance and climate variability interactively affect total streamflow, baseflow, and surface runoff. Baseflow was separated using a combination of the recursive digital filter method and conductivity mass balance method. Time series analysis and modified double mass curves were then employed to quantitatively separate the relative contributions of forest disturbance and climate variability to each streamflow component. Our results showed that average annual baseflow and baseflow index (baseflow/streamflow) were 113.3 ± 35.6 mm year−1 and 0.27 for 1954–2013, respectively. Forest disturbance increased annual streamflow, baseflow, and surface runoff of 27.7 ± 13.7 mm, 7.4 ± 3.6 mm, and 18.4 ± 12.9 mm, respectively, with its relative contributions to the changes in respective streamflow components being 27.0 ± 23.0%, 29.2 ± 23.1%, and 25.7 ± 23.4%, respectively. In contrast, climate variability decreased them by 74.9 ± 13.7 mm, 17.9 ± 3.6 mm, and 53.3 ± 12.9 mm, respectively, with its relative contributions to the changes in respective streamflow components being 73.0 ± 23.0%, 70.8 ± 23.1% and 73.1 ± 23.4%, respectively. Despite working in opposite ways, the impacts of climate variability on annual streamflow, baseflow, and surface runoff were of a much greater magnitude than forest disturbance impacts. This study has important implications for the protection of aquatic habitat, engineering design, and watershed planning in the context of future forest disturbance and climate change.
A plant growth-promoting and antifungal endophytic bacteria designated as Ld-08 isolated from the bulbs of Lilium davidii was identified as Pseudomonas aeruginosa based on phenotypic, microscopic, ...and 16S rRNA gene sequence analysis. Ld-08 exhibited antifungal effects against Fusarium oxysporum, Botrytis cinerea, Botryosphaeria dothidea, and Fusarium fujikuroi. Ld-08 showed the highest growth inhibition, i.e., 83.82±4.76% against B. dothidea followed by 74.12±3.87%, 67.56±3.35%, and 63.67±3.39% against F. fujikuroi, B. cinerea, and F. oxysporum, respectively. The ethyl acetate fraction of Ld-08 revealed the presence of several bioactive secondary metabolites. Prominent compounds were quinolones; 3,9-dimethoxypterocarpan; cascaroside B; dehydroabietylamine; epiandrosterone; nocodazole; oxolinic acid; pyochelin; rhodotulic acid; 9,12-octadecadienoic acid; di-peptides; tri-peptides; ursodiol, and venlafaxine. The strain Ld-08 showed organic acids, ACC deaminase, phosphate solubilization, IAA, and siderophore. The sterilized bulbs of a Lilium variety, inoculated with Ld-08, were further studied for plant growth-promoting traits. The inoculated plants showed improved growth than the control plants. Importantly, some growth parameters such as plant height, leaf length, bulb weight, and root length were significantly (P less than or equal to0.05) increased in the inoculated plants than in the control un-inoculated plants. Further investigations are required to explore the potential of this strain to be used as a plant growth-promoting and biocontrol agent in sustainable agriculture.
► Forest harvesting produced significant positive impact on annual runoff. ► Forest harvesting decreased dry season runoff. ► Forest harvesting and climatic variability had offsetting effects on ...annual runoff. ► The effect of forest harvesting on runoff diminished about 20yrs after intensive harvesting period.
Forest disturbance (or land cover change) and climatic variability are commonly recognized as two major drivers interactively influencing hydrology in forested watersheds. However, separating their relative contributions to hydrology is rarely examined, particularly in large watersheds (>1000km2). This study used a large watershed, the Upper Zagunao River watershed, situated in the upper reach of the Minjiang River, the Yangtze River basin, China as an example to demonstrate how the effects of forest harvesting and climatic variability on hydrology can be quantitatively separated. Long-term data on climate, hydrology and forest harvesting history are available from1953 to 1996. Time series cross-correlation analysis and non-parametric tests were performed first to identify possible responses of annual and seasonal runoff to forest harvesting, and to determine breakpoints of runoff change over its long-term time series. Then, modified double mass curve of accumulated annual effective precipitation (the residual of precipitation and evapotranspiration) and accumulated annual runoff was used to quantify the relative contributions of forest harvesting and climatic variability to annual runoff variation. Our analysis showed that the breakpoint of significant annual runoff change occurred in1969, about 10yrs after the intensive harvesting period of 1955–1962, suggesting the delayed hydrological response in the studied large watershed. Over the period of 1970–1996, the average annual runoff increment attributed to forest harvesting was 38mm/yr, while the annual runoff variation attributed to climatic variability was −38.3mm/yr, clearly demonstrating that forest harvesting and climatic variability had offsetting effects on annual runoff. Our results also disclosed that the positive effect of forest harvesting on runoff decreased with forest recovery and eventually diminished about 20yrs after intensive harvesting period.
Summary
Recessive resistances to plant viruses in the Potyvirus genus have been found to be based on mutations in the plant eukaryotic translation initiation factors, eIF4E and eIF4G or their ...isoforms. Here we report that natural, monogenic recessive resistance to the Potyvirus Turnip mosaic virus (TuMV) has been found in a number of mustard (Brassica juncea) accessions. Bulked segregant analysis and sequencing of resistant and susceptible plant lines indicated the resistance is controlled by a single recessive gene, recessive TuMV resistance 03 (retr03), an allele of the eukaryotic translation initiation factor 2B‐beta (eIF2Bβ). Silencing of eIF2Bβ in a TuMV‐susceptible mustard plant line and expression of eIF2Bβ from a TuMV‐susceptible line in a TuMV‐resistant mustard plant line confirmed the new resistance mechanism. A functional copy of a specific allele of eIF2Bβ is required for efficient TuMV infection. eIF2Bβ represents a new class of virus resistance gene conferring resistance to any pathogen. eIF2B acts as a guanine nucleotide exchange factor (GEF) for its GTP‐binding protein partner eIF2 via interaction with eIF2·GTP at an early step in translation initiation. Further genotyping indicated that a single non‐synonymous substitution (A120G) in the N‐terminal region of eIF2Bβ was responsible for the TuMV resistance. A reproducible marker has been developed, facilitating marker‐assisted selection for TuMV resistance in B. juncea. Our findings provide a new target for seeking natural resistance to potyviruses and new opportunities for the control of potyviruses using genome editing techniques targeted on eIF2Bβ.
Significance Statement
We identified for the first time the eIF2Bβ gene conferring resistance to Turnip mosaic virus in B. juncea, representing a new class of plant virus resistance gene. Our findings provide a new target for seeking natural resistance to potyviruses and new opportunities for the control of potyviruses using genome editing techniques targeted on eIF2Bβ.
Interferon-induced transmembrane protein 1 (IFITM1), a 17-kDa membrane protein, is generally known as a modulator in many cellular functions. Recent studies showed overexpression of IFITM1 in cancers ...and relationship between IFITM1 overexpression and tumor progression. However, the role of IFITM1 in lung cancer remains unclear. Here, we presented the overexpression of IFITM1 in lung cancer tissues and cell lines A549 and H460 using quantitative Real-Time RT-PCR. In vitro assay indicated IFITM1 silencing inhibited lung cancer cell proliferation, migration, and invasion. Further, in vivo assay showed that IFITM1 silencing markedly suppressed cell growth and metastasis of lung cancer in tumor-bearing BALB/c nude mice. Mechanistically, we found that IFITM1 silencing significantly alleviated the protein levels of β-catenin, cyclin D1, and c-Mycin lung cancer cells and tumor samples. Taken together, our study revealed the role of IFITM1 as a tumor promoter during lung cancer development and the possible molecular mechanism.
The ULK complex initiates the autophagosome formation, and has recently been implicated in selective autophagy by interacting with autophagy receptors through its FIP200 subunit. However, the ...structural mechanism underlying the interactions of autophagy receptors with FIP200 and the relevant regulatory mechanism remain elusive. Here, we discover that the interactions of FIP200 Claw domain with autophagy receptors CCPG1 and Optineurin can be regulated by the phosphorylation in their respective FIP200-binding regions. We determine the crystal structures of FIP200 Claw in complex with the phosphorylated CCPG1 and Optineurin, and elucidate the detailed molecular mechanism governing the interactions of FIP200 Claw with CCPG1 and Optineurin as well as their potential regulations by kinase-mediated phosphorylation. In addition, we define the consensus FIP200 Claw-binding motif, and find other autophagy receptors that contain this motif within their conventional LC3-interacting regions. In all, our findings uncover a general and phosphoregulatable binding mode shared by many autophagy receptors to interact with FIP200 Claw for autophagosome biogenesis, and are valuable for further understanding the molecular mechanism of selective autophagy.
Regulatory network of cytoplasmic male sterility (CMS) occurrence is still largely unknown in plants, although numerous researches have been attempted to isolate genes involved in CMS. Here, we ...employed high-throughput sequencing and degradome analysis to identify microRNAs and their targets using high-throughput sequencing in CMS and its maintainer fertile (MF) lines of Brassica juncea.
We identified 197 known and 78 new candidate microRNAs during reproductive development of B. juncea. A total of 47 differentially expressed microRNAs between CMS and its MF lines were discovered, according to their sequencing reads number. Different expression levels of selected microRNAs were confirmed by using real-time quantitative PCR between CMS and MF lines. Furthermore, we observed that the transcriptional patterns of these microRNAs could be mimicked by artificially inhibiting mitochondrial F1F0-ATPase activity and its function in MF line by using treatment with oligomycin. Targeted genes of the microRNAs were identified by high-throughput sequencing and degradome approaches, including auxin response factor, NAC (No Apical Meristem) domain transcription factor, GRAS family transcription factor, MYB transcription factor, squamosa promoter binding protein, AP2-type transcription factor, homeobox/homeobox-leucine zipper family and TCP family transcription factors, which were observed to be differentially expressed between CMS and MF.
Taken together, from these findings we suggested microRNA might participate in the regulatory network of CMS by tuning fork in gene expressions in CMS B. juncea. The differential expression of miRNAs observed between CMS and MF lines suggested that biogenesis of miRNAs could be influenced in the CMS.
The present study was aimed at isolating endophytic fungi from the Asian culinary and medicinal plant Lilium davidii and analyzing its antifungal and plant growth-promoting effects. In this study, ...the fungal endophyte Acremonium sp. Ld-03 was isolated from the bulbs of L. davidii and identified through morphological and molecular analysis. The molecular and morphological analysis confirmed the endophytic fungal strain as Acremonium sp. Ld-03. Antifungal effects of Ld-03 were observed against Fusarium oxysporum, Botrytis cinerea, Botryosphaeria dothidea, and Fusarium fujikuroi. The highest growth inhibition, i.e., 78.39±4.21%, was observed for B. dothidea followed by 56.68±4.38%, 43.62±3.81%, and 20.12±2.45% for B. cinerea, F. fujikuroi, and F. oxysporum, respectively. Analysis of the ethyl acetate fraction through UHPLC-LTQ-IT-MS/MS revealed putative secondary metabolites which included xanthurenic acid, valyl aspartic acid, gancidin W, peptides, and cyclic dipeptides such as valylarginine, cyclo-L-(4-hydroxy-Pro)-L-leu, cyclo(Pro-Phe), and (3S,6S)-3-benzyl-6-(4-hydroxybenzyl)piperazine-2,5-dione. Other metabolites included (S)-3-(4-hydroxyphenyl)-2-((S)-pyrrolidine-2-carboxamido)propanoic acid, dibutyl phthalate (DBP), 9-octadecenamide, D-erythro-C18-Sphingosine, N-palmitoyl sphinganine, and hydroxypalmitoyl sphinganine. The strain Ld-03 showed indole acetic acid (IAA) production with or without the application of exogenous tryptophan. The IAA ranged from 53.12±3.20 μg ml-1 to 167.71±7.12 μg ml-1 under different tryptophan concentrations. The strain was able to produce siderophore, and its production was significantly decreased with increasing Fe(III) citrate concentrations in the medium. The endophytic fungal strain also showed production of organic acids and phosphate solubilization activity. Plant growth-promoting effects of the strain were evaluated on in vitro seedling growth of Allium tuberosum. Application of 40% culture dilution resulted in a significant increase in root and shoot length, i.e., 24.03±2.71 mm and 37.27±1.86 mm, respectively, compared to nontreated control plants. The fungal endophyte Ld-03 demonstrated the potential of conferring disease resistance and plant growth promotion. Therefore, we conclude that the isolated Acremonium sp. Ld-03 should be further investigated before utilization as a biocontrol agent and plant growth stimulator.
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