Enhancement of Sesquiterpenoid Production by Methyl Jasmonate in Atractylodes chinensis Adventitious Root Culture and its Transcriptional Regulation.

The adventitious root (AR) culture of Atractylodes chinensis is an efficient platform for sustainable production of its sesquiterpenoid compounds (atractylon and ß-eudesmol). However, their limited accumulation levels need an effective elicitation approach, and the present study solved this problem using methyl jasmonate (MeJA) as an elicitor. The effects of its treatment concentration and duration on metabolite production were investigated. The ARs treated with 100 µM MeJA for seven days increased atractylon and ß-eudesmol by 3.64- and 1.90-fold, respectively, compared with the control. This study further performed transcriptome analysis to explore the transcriptional regulation mechanism of the MeJA elicitation. A total of 124,464 unigenes were identified in A. chinensis ARs, of which 3,568 genes were upregulated and 3,864 genes were downregulated under the MeJA treatment. The MeJA treatment activated the endogenous JA biosynthesis and signaling pathways and sesquiterpenoid biosynthesis. The MeJA treatment more significantly activated the MEP pathway than the MVA pathway. In addition, 14 genes encoding terpene synthase were identified to be significantly upregulated. A total of 2,700 transcription factors (TFs) were identified in A. chinensis ARs, of which Tify, MYB, and MADS were significantly enriched under the MeJA treatment. We predicted a new antagonistic interaction between MYC2 and CPP TFs, which was significantly regulated by the MeJA treatment. The results of real-time quantitative PCR and enzyme activity assays proved the reliability of the transcriptome data. This study will help improve the in vitro production system of A. chinensis sesquiterpenoids and understand the transcriptional regulation mechanism of MeJA elicitation.

Melatonin alleviates UV-B stress and enhances phenolic biosynthesis in rosemary (Rosmarinus officinalis) callus.

Although used in in vitro culture to boost secondary metabolite production, UV-B radiation can seriously affect plant growth if not properly dosed. Rosemary callus can be used as an important source of effective ingredients in the food and medicine industry. To balance the positive and negative effects of UV-B on rosmary callus, this study investigated the effects of melatonin on rosemary callus under UV-B radiation. The results showed that melatonin improved rosemary callus growth, with fresh weight and dry weight increased by 15.81% and 8.30%, respectively. The addition of 100 µM melatonin increased antioxidant enzyme activity and NO content in rosemary callus. At the same time, melatonin also significantly reduced membrane lipid damage and H2O2 accumulation in rosemary callus under UV-B stress, with malondialdehyde (MDA) and H2O2 contents reduced by 13.03% and 14.55%, respectively. In addition, melatonin increased the total phenol and rosmarinic acid contents in rosemary callus by 19% and 54%, respectively. Melatonin significantly improved the antioxidant activity of the extracts from rosemary callus. These results suggest that exogenous melatonin can alleviate the adverse effects of UV-B stress on rosemary callus by promoting NO accumulation while further enhancing phenolic accumulation and biological activity.

Perceived Value, Government Regulations, and Farmers' Agricultural Green Production Technology Adoption: Evidence from China's Yellow River Basin.

Farmers' agricultural green production technology (AGPT) adoption behavior has attracted extensive attention, while few studies explored the interactive effect of perceived value and government regulations in this process. Therefore, we analyze the interaction effect between perceived value and different government regulations on farmers' AGPT adoption by the Poisson regression model, using micro-survey data from 1491 households in China's Yellow River basin. Furthermore, we examine the heterogeneous effect of perceived value and government regulations on farmers' AGPT adoption behavior considering the change in production scale and farmers' age. The results suggest that perceived value can substitute for incentive government regulation and guiding government regulation, respectively. While binding government regulation can inhibit the promotion effect of perceived value on farmers' AGPT adoption. In addition, the larger the production scale, the more influential the effects of perceived value and government regulations on farmers' AGPT adoption are. In contrast, with the increase in farmer's age, the promotion effect of perceived value becomes weak while the effect of government regulations experiences a U-shaped trend. Finally, the conclusions and policy implications are set forth.

Feasibility of urban bird occurrence and nest amount evaluation by the street-view image virtual survey.

Bird observation mainly relies on field surveys, which are time-consuming and laborious. In this study, we explored using street-view images in the virtual survey of urban birds and nests. Using the coastal city of Qingdao as the study area, 47 201 seamless spherical photos at 2741 sites were collected using the Baidu street-view (BSV) map. Single-rater-all photo checks and seven-rater-metapopulation checks were used to find inter-rater repeatability, the best viewing layer for BSV collection, and possible environments affecting the results. We also collected community science data for comparison. The BSV time machine was used to assess the temporal dynamics. Kappa square test, generalized linear model, redundancy ordination and ArcMap were used in the analysis. Different rater repeatability was 79.1% in nest evaluations and 46.9% in bird occurrence. A re-check of the different-rating photos can increase them to 92% and 70%. Seven-rater statistics showed that more than 5% sampling ratio could produce a non-significant different bird and nest percentage of the whole data, and the higher sampling ratio could reduce the variation. The middle-viewing layer survey alone could produce 93% precision of the nest checks by saving 2/3 of the time used; in birds, selecting middle and upper-view photos could find 97% of bird occurrences. In the spatial distribution, the nest's hotspot areas from this method were much greater than the community science bird-watching sites. The BSV time machine made it possible to re-check nests in the same sites but challenging the re-check of bird occurrences. The nests and birds can be observed more in the leafless season, on wide, traffic-dense coastal streets with complex vertical structures of trees, and in the gaps of tall buildings dominated by road forests. Our results indicate that BSV photos could be used to virtually evaluate bird occurrence and nests from their numbers, spatial distribution and temporal dynamics. This method provides a pre-experimental and informative supplement to large-scale bird occurrence and nest abundance surveys in urban environments.

Melatonin enhances biomass, phenolic accumulation, and bioactivities of rosemary (Rosmarinus officinalis) in vitro shoots under UV-B stress.

Melatonin is a stress-related hormone that plays a critical role in triggering the plant defence system and regulating secondary metabolism when plants are exposed to stress. To explore the potential roles of melatonin in response to Ultraviolet-B (UV-B) radiation, we examined the effects of exogenous melatonin on rosemary in vitro shoots under UV-B stress. The application of melatonin (50 µM) alleviated the adverse effects of UV-B stress on the biomass, photosynthetic pigment contents, and membrane lipids of the rosemary in vitro shoots. Melatonin significantly increased superoxide dismutase (1.15.1.1, SOD), peroxidase (1.11.1.7, POD), and catalase (1.11.1.6, CAT) activities by 62%, 99%, and 53%, respectively. The contents of total phenols, rosmarinic acid, and carnosic acid increased under UV-B stress, and they further increased by the melatonin treatment by 41%, 68%, and 67%, respectively, compared with the control group. Under UV-B stress, the increased total phenol content in melatonin-pretreated plants could be attributed to the activation of phenylalanine ammonia-lyase (4.3.1.5, PAL) and tyrosine aminotransferase (2.6.1.5, TAT). In addition, melatonin enhanced the antioxidant and antibacterial activities of the rosemary in vitro shoots under UV-B stress. These results suggest that melatonin can alleviate the damage caused by UV-B stress and also enhance the secondary metabolism and bioactivity of rosemary in vitro shoots.

The role of climate-adaptive technological innovation in promoting agriculture carbon efficiency: impact and heterogeneity in economic development.

Achieving global climate change mitigation targets requires low-carbon production in agriculture. In such an endeavor, a new classification of climate-adaptive technology is defined to affect agriculture towards the low-carbon direction, but such an impact has seldom been empirically tested in the literature. In this paper, we investigate the impact of climate-adaptive technological innovation on agricultural carbon efficiency, a proxy for low-carbon agriculture. We use a stochastic directional distance function framework and a cross-country dataset covering 38 OECD countries. Additionally, we test the heterogeneous impact, considering that regional economic development is a crucial condition for deploying advanced technologies. The findings show that climate-adaptive technological innovation can promote carbon efficiency in agriculture, and this aggregate effect hides significant heterogeneity at different levels of economic development. The higher the economic development level is, the better climate-adaptive technological innovation contributes to improving agricultural carbon efficiency. Then, related policy implications are set forth.

Spatial-temporal and structural differences in the carbon footprints embedded in households food waste in urban and rural China.

Household food waste (HFW) accounted for about 66% of global food waste's total carbon footprints (CF). Based on China's macro-panel food consumption data, this paper measures the urban-rural and provincial differences in the HFW CF from scale, structure, and temporal-spatial evolution perspectives. The results indicate that HFW and CF continue to grow, and the total CF and per capita HFW in urban households are higher than in rural households. The structural differences between urban and rural HFW CF vary significantly over time and spaces, which reflected that rural households in the southeastern coastal areas have higher per capita HFW CF than urban in 2019. The research results help to clarify the distribution and evolution pattern of HFW CF in China and offer new ideas for the differentiated governance of CF reduction in the food system.

The Psychological Process of Residents' Acceptance of Local Shale Gas Exploitation in China.

Local communities and their opinion on shale gas exploitation (SGE) play an essential role in the implementation of energy policies, while little is known about the reasoning process underpinning the acceptance of SGE. The present study develops a conceptual framework to examine the psychological process of residents' acceptance of local SGE, in which the impacts of trust, knowledge, and fairness are mediated by risk and benefit perceptions. Structural equation modeling has been applied to analyze the hypothesized relationships based on a dataset of 825 households in China's largest shale gas field. Our results indicate that residents' perceived fairness and trust positively affect their benefit perceptions and negatively affect their risk perceptions, which results in positive influences on acceptance, and knowledge of SGE's environmental impacts positively affects perceived risks, which results in a negative influence on acceptance. Moreover, residents' acceptance is primarily determined by their benefit perception, followed by perceived fairness, and knowledge is the least important determinant. Thus, our study contributes to the literature by exploring the structural relationships between various psychological predictors and the acceptance toward SGE, and the results from our empirical survey provide insight into designing appropriate strategies in the process of generating and communicating shale policies.

'Get a Fish' vs. 'Get a Fishing Skill': Farmers' Preferred Compensation Methods to Control Agricultural Nonpoint Source Pollution.

Ecological compensation is an important means for controlling agricultural nonpoint source pollution, and compensation methods comprise an essential part of the compensation policy for mitigating this form of pollution. Farmers' choice of compensation methods affects their response to compensation policies as well as the effects of pollution control and ecological compensation efficiency. This study divides ecological compensation methods into two distinct philosophies-the "get a fish" method (GFM) and "get a fishing skill" method (GFSM)-based on policy objectives, to determine farmers' choice between the two methods and the factors influencing this choice. Furthermore, by analyzing survey data of 632 farmers in the Ankang and Hanzhong cities in China and using the multivariate probit model, the study determines farmers' preferred option among four specific compensation modes of GFM and GFSM. The three main results are as follows. (1) The probability of farmers choosing GFM is 82%, while that of choosing GFSM is 51%. Therefore, GFM should receive more attention in compensation policies relating to agricultural nonpoint source pollution control. (2) Of the four compensation modes, the study finds a substitution effect between farmers' choice of capital and technology compensations, capital and project compensations, material and project compensations, while there is a complementary relationship between the choice of material and technology compensations. Therefore, when constructing the compensation policy basket, attention should be given to achieving an organic combination of different compensation methods. (3) Highly educated, young, and male farmers with lower part-time employment, large cultivated land, and a high level of eco-friendly technology adoption and policy understanding are more likely to choose GFSM. Hence, the government should prioritize promoting GFSM for farmers with these characteristics, thereby creating a demonstration effect to encourage transition from GFM to GFSM.

Explaining Local Residents' Attitudes toward Shale Gas Exploitation: The Mediating Roles of Risk and Benefit Perceptions.

Using Fishbein's multi-attribute model, this paper proposes that the impact of socio-demographic and psychosocial factors on local residents' overall attitude toward shale gas exploitation (SGE) is mediated by their risk and benefit perceptions. The proposition has been validated with the generalized structural equation modeling approach with a cross-sectional dataset of 825 residents from China's Fuling shale gas field. Results indicate that the influence of benefit perception on residents' overall attitude outweighs that of risk perception. Moreover, residents' perceived fairness, affective feeling, and trust in regulatory agencies have positive influences on their overall attitude, primarily via their risk and benefit perceptions, in decreasing order of influences. Finally, we also find that residents' attitudes have been significantly influenced by their socio-demographic factors, including age, residential area, and political ideology. Thus, our study extends the literature with theoretical and empirical models by exploring the influences factors of local residents' attitudes toward SGE, and results from our empirical survey provide insight into policy design to promote the acceptance of SGE.