Nitrous oxide (N2O) is a greenhouse gas that also plays the primary role in stratospheric ozone depletion. The use of nitrogen fertilizers is known as the major reason for atmospheric N2O increase. ...Empirical bottom‐up models therefore estimate agricultural N2O inventories using N loading as the sole predictor, disregarding the regional heterogeneities in soil inherent response to external N loading. Several environmental factors have been found to influence the response in soil N2O emission to N fertilization, but their interdependence and relative importance have not been addressed properly. Here, we show that soil pH is the chief factor explaining regional disparities in N2O emission, using a global meta‐analysis of 1,104 field measurements. The emission factor (EF) of N2O increases significantly (p < .001) with soil pH decrease. The default EF value of 1.0%, according to IPCC (Intergovernmental Panel on Climate Change) for agricultural soils, occurs at soil pH 6.76. Moreover, changes in EF with N fertilization (i.e. ΔEF) is also negatively correlated (p < .001) with soil pH. This indicates that N2O emission in acidic soils is more sensitive to changing N fertilization than that in alkaline soils. Incorporating our findings into bottom‐up models has significant consequences for regional and global N2O emission inventories and reconciling them with those from top‐down models. Moreover, our results allow region‐specific development of tailor‐made N2O mitigation measures in agriculture.
We identified soil pH as the chief factor modifying regional response in N2O emission to N fertilization, based on an updated global meta‐analysis of 1,104 field measurements. Both N2O emission factor (i.e. EF) and nonlinearity coefficient (i.e. ΔEF) were found to negatively correlated with soil pH. Incorporating our findings into bottom‐up models could help to construct sound global N2O inventories, to reconcile the discrepancies between top‐down and bottom‐up N2O estimates, and to develop optimized region‐specific measures for N2O mitigation from agriculture.
Healthcare is the sector that was significantly changed by the arrival of mobile devices. This study investigates how an individual using smartphones impact quality of life by changing his or her ...health information behavior. Our results show that individuals with a smartphone are more likely to seek and track their health information than those who with a regular cell phone, and consequently, the former experience a better quality of life. Moreover, using smartphone more likely leads to seek health information for care-givers than non-caregivers, as well as for the younger individuals than the older.
China is the world's largest producer and consumer of fertilizer N, and decades of overuse has caused nitrate leaching and possibly soil acidification. We hypothesized that this would enhance the ...soils' propensity to emit N₂O from denitrification by reducing the expression of the enzyme N₂O reductase. We investigated this by standardized oxic/anoxic incubations of soils from five long‐term fertilization experiments in different regions of China. After adjusting the nitrate concentration to 2 mM, we measured oxic respiration (R), potential denitrification (D), substrate‐induced denitrification, and the denitrification product stoichiometry (NO, N₂O, N₂). Soils with a history of high fertilizer N levels had high N₂O/(N₂O+N₂) ratios, but only in those field experiments where soil pH had been lowered by N fertilization. By comparing all soils, we found a strong negative correlation between pH and the N₂O/(N₂O+N₂) product ratio (r² = 0.759, P < 0.001). In contrast, the potential denitrification (D) was found to be a linear function of oxic respiration (R), and the ratio D/R was largely unaffected by soil pH. The immediate effect of liming acidified soils was lowered N₂O/(N₂O+N₂) ratios. The results provide evidence that soil pH has a marginal direct effect on potential denitrification, but that it is the master variable controlling the percentage of denitrified N emitted as N₂O. It has been known for long that low pH may result in high N₂O/(N₂O+N₂) product ratios of denitrification, but our documentation of a pervasive pH‐control of this ratio across soil types and management practices is new. The results are in good agreement with new understanding of how pH may interfere with the expression of N₂O reductase. We argue that the management of soil pH should be high on the agenda for mitigating N₂O emissions in the future, particularly for countries where ongoing intensification of plant production is likely to acidify the soils.
Background
Salt stress is one of the main abiotic stresses that limits rice production worldwide. Rice salt tolerance at the bud burst stage directly affects the seedling survival rate and the final ...yield in the direct seeding cultivation model. However, the reports on quantitative trait locus (QTL) mapping and map-based cloning for salt tolerance at the bud burst stage are limited.
Results
Here, an F
2:3
population derived from a cross between IR36 (salt-sensitive) and Weiguo (salt-tolerant) was used to identify salt-tolerant QTL interval at the bud burst stage using a whole-genome sequencing-based QTL-seq containing 40 extreme salt-tolerant and 40 extreme salt-sensitive individuals. A major QTL,
qRSL7
, related to relative shoot length (RSL) was detected on chromosome 7 using ΔSNP index algorithms and Euclidean Distance (ED) algorithms. According to single nucleotide polymorphisms (SNPs) between the parents, 25 Kompetitive allele-specific PCR (KASP) markers were developed near
qRSL7
, and regional QTL mapping was performed using 199 individuals from the F
2:3
population. We then confirmed and narrowed down
qRSL7
to a 222 kb genome interval. Additionally, RNA sequencing (RNA-seq) was performed for IR36 and Weiguo at 36 h after salt stress and control condition at the bud burst stage, and 5 differentially expressed genes (DEGs) were detected in the candidate region. The qRT-PCR results showed the same expression patterns as the RNA-seq data. Furthermore, sequence analysis revealed a 1 bp Indel difference in
Os07g0569700
(
OsSAP16
) between IR36 and Weiguo.
OsSAP16
encodes a stress-associated protein whose expression is increased under drought stress.
Conclusion
These results indicate that
OsSAP16
was the candidate gene of
qRSL7
. The results is useful for gene cloning of
qRSL7
and for improving the salt tolerance of rice varieties by marker assisted selection (MAS).
This research presents an integrated information processing model of phishing susceptibility grounded in the prior research in information process and interpersonal deception. We refine and validate ...the model using a sample of intended victims of an actual phishing attack. The data provides strong support for the model's theoretical structure and causative sequence. Overall, the model explains close to 50% of the variance in individual phishing susceptibility. The results indicate that most phishing emails are peripherally processed and individuals make decisions based on simple cues embedded in the email. Interestingly, urgency cues in the email stimulated increased information processing thereby short circuiting the resources available for attending to other cues that could potentially help detect the deception. Additionally, the findings suggest that habitual patterns of media use combined with high levels of email load have a strong and significant influence on individuals' likelihood to be phished. Consistent with social cognitive theory, computer self-efficacy was found to significantly influence elaboration, but its influence was diminished by domain specific-knowledge.
Background
Salinity-alkalinity stress is one of the major factors limiting rice production. Damage caused by alkaline salt stress is more severe than that caused by neutral salt stress. Alkali ...tolerance at the bud stage in rice directly affects seedling survival and final yield when using the direct seeding cultivation model. However, genetic resources (QTLs and genes) for rice breeders to improve alkali tolerance are limited. In this study, we combined linkage mapping and a genome-wide association study (GWAS) to analyze the genetic structure of this trait in
japonica
rice at the bud stage.
Results
A population of 184 recombinant inbred lines (RILs) was utilized to map quantitative trait loci (QTLs) for the root length under control condition (RL), alkaline stress (ARL) and relative root length (RRL) at the bud stage. A major QTL related to alkali tolerance at the rice bud stage,
qAT11
, was detected on chromosome 11. Interestingly, a GWAS identified a lead SNP (Chr_21,999,659) in
qAT11
that was significantly associated with alkaline tolerance. After filtering by linkage disequilibrium (LD), haplotype analysis, quantitative real-time PCR, we obtained three candidate genes (
LOC_Os11g37300
,
LOC_Os11g37320
and
LOC_Os11g37390
). In addition, we performed phenotype verification on the CRISPR/Cas9 mutant of
LOC_Os11g37390
.
Conclusion
Based on these results,
LOC_Os11g37300
,
LOC_Os11g37320
and
LOC_Os11g37390
were the candidate genes contributing to alkaline tolerance in
japonica
rice. This study provides resources for breeding aimed at improving rice responses to alkalinity stress.
With the goal of improving N fertilizer management to maximize soil organic carbon (SOC) storage and minimize N losses in high-intensity cropping system, a 6-years greenhouse vegetable experiment was ...conducted from 2004 to 2010 in Shouguang, northern China. Treatment tested the effects of organic manure and N fertilizer on SOC, total N (TN) pool and annual apparent N losses. The results demonstrated that SOC and TN concentrations in the 0-10cm soil layer decreased significantly without organic manure and mineral N applications, primarily because of the decomposition of stable C. Increasing C inputs through wheat straw and chicken manure incorporation couldn't increase SOC pools over the 4 year duration of the experiment. In contrast to the organic manure treatment, the SOC and TN pools were not increased with the combination of organic manure and N fertilizer. However, the soil labile carbon fractions increased significantly when both chicken manure and N fertilizer were applied together. Additionally, lower optimized N fertilizer inputs did not decrease SOC and TN accumulation compared with conventional N applications. Despite the annual apparent N losses for the optimized N treatment were significantly lower than that for the conventional N treatment, the unchanged SOC over the past 6 years might limit N storage in the soil and more surplus N were lost to the environment. Consequently, optimized N fertilizer inputs according to root-zone N management did not influence the accumulation of SOC and TN in soil; but beneficial in reducing apparent N losses. N fertilizer management in a greenhouse cropping system should not only identify how to reduce N fertilizer input but should also be more attentive to improving soil fertility with better management of organic manure.
Rockwool (RC) and peat are two common substrates used worldwide in horticultural crop production. In recent years environmental and ecological concerns raised the demand for reducing the use of RC ...and peat. Although coconut coir (CC) has been increasingly used as an alternative to RC and peat, it is still needed to comprehensively evaluate the feasibility of CC before widely used. To meet this need, CC, RC, and peat-vermiculite (PVC) cultivations were used as tomato cultivation substrates to evaluate their effects on EC, pH and mineral ions in root-zone solution and drainage, nutrient uptake by crops, nutrient balance of cultivation system, plant growth and fruit quality. In general, CC significantly increased K and S uptake by crops, photosynthesis, individual fruit weight and total fruit yield compared to RC, and increased P and K uptake by crops and total fruit yield compared to PVC. Moreover, CC significantly increased organic acid of fruit in first truss compared to both RC and PVC. The uncredited nutrient was overally lower under CC than under RC and PVC (the lower, the better). For all substrates, the blossom-end rot (BER) of fruit increased gradually from 3rd to 13th trusses. The BER of fruit was not significantly influenced by CC compared to RC or PVC, but was sginificantly decreased by PVC compared to RC. Our results infer that CC was a potential substrate that could be widely used in tomato production. However, the inhibition of BER was still a challenge when CC was used as cultivation substrate for tomato.
Rice (Oryza sativa L.) is one of the most widely grown food crops, and its yield and quality are particularly important for a warm-saturated diet. Cold stress restricts rice growth, development, and ...yield; however, the specific mechanism of cold tolerance in rice remains unknown.
The analysis of leaf physiological and photosynthetic characteristics showed that the two rice varieties were significantly affected by cold stress, but the cold-tolerant variety KY131 had more stable physiological characteristics, maintaining relatively good photosynthetic capacity. To better explore the transcriptional regulation mechanism and biological basis of rice response to cold stress, a comprehensive analysis of the rice transcriptome and lipidome under low temperature and control temperature conditions was carried out. The transcriptomic analysis revealed that lipid metabolism, including membrane lipid and fatty acid metabolism, may be an important factor in rice cold tolerance, and 397 lipid metabolism related genes have been identified. Lipidomics data confirmed the importance of membrane lipid remodeling and fatty acid unsaturation for rice adaptation to cold stress. This indicates that the changes in the fluidity and integrity of the photosynthetic membrane under cold stress lead to the reduction of photosynthetic capacity, which could be relieved by increased levels of monogalactosyldiacylglycerol that mainly caused by markedly increased expression of levels of 1,2-diacylglycerol 3-beta-galactosyltransferase (MGD). The upregulation of phosphatidate phosphatase (PAP2) inhibited the excessive accumulation of phosphatidate (PA) to produce more phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylglycerol (PG), thereby preventing of membrane phase transition under cold stress. In addition, fatty acid β-oxidation is worth further study in rice cold tolerance. Finally, we constructed a metabolic model for the regulatory mechanism of cold tolerance in rice, in which the advanced lipid metabolism system plays a central role.
Lipidome analysis showed that membrane lipid composition and unsaturation were significantly affected, especially phospholipids and galactolipids. Our study provides new information to further understand the response of rice to cold stress.
Caffeic acid O-methyltransferase (COMT) is one of the core enzymes involved in lignin synthesis. However, there is no systematic study on the rice COMT gene family. We identified 33 COMT genes ...containing the methyltransferase-2 domain in the rice genome using bioinformatic methods and divided them into Group I (a and b) and Group II. Motifs, conserved domains, gene structure and SNPs density are related to the classification of OsCOMTs. The tandem phenomenon plays a key role in the expansion of OsCOMTs. The expression levels of fourteen and thirteen OsCOMTs increased or decreased under salt stress and drought stress, respectively. OsCOMTs showed higher expression levels in the stem. The lignin content of rice was measured in five stages; combined with the expression analysis of OsCOMTs and multiple sequence alignment, we found that OsCOMT8, OsCOMT9 and OsCOMT15 play a key role in the synthesis of lignin. Targeted miRNAs and gene ontology annotation revealed that OsCOMTs were involved in abiotic stress responses. Our study contributes to the analysis of the biological function of OsCOMTs, which may provide information for future rice breeding and editing of the rice genome.
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