Spatiotemporal variations of fossil fuel CO2 emissions in China: A sectoral allocation approach based on multi-source data.

Fossil fuel (FF) CO2 emissions account for the largest portion of human-related CO2 emissions. It is essential to accurately understand the spatial distribution of high-resolution FFCO2 emissions to formulate different carbon emission reduction policies in different regions. Therefore, a sectoral allocation approach was proposed to estimate FFCO2 emissions in China from 2000 to 2021 based on multi-source data. Furthermore, the spatiotemporal characteristics of FFCO2 emissions in different sectors were analyzed at different scales, and the spatial correlation of FFCO2 emissions in the service sector and industrial sector was also evaluated through Moran's index. The results showed that the mean R2 value of the sectoral allocation approach (0.89) exceeds that of the approach using only nighttime light (0.72). Moreover, the calculated results were utilized to analyze the Spatiotemporal variation of FFCO2 emissions. The analysis revealed that China's FFCO2 emissions increased from 3173 Mt in 2000-10662 Mt in 2021. The high emissions of FFCO2 mainly come from the industrial sectors in North China and Central China, as well as the service sectors in the eastern coastal cities and other provincial capital cities. The spatial dependence of FFCO2 emissions in the industrial sector was stronger than that in the service sector, but the spatial dependence of FFCO2 emissions in the service sector showed an increasing trend from 2000 to 2021. These results have important references and implications for region-specific carbon emission reduction policies.

Carbon emission change based on land use in Gansu Province.

Carbon emissions from land use change have become one of the main sources of regional carbon emissions. In order to explore the changes, 87 districts and counties in Gansu Province are taken as research objects. Based on the remote sensing data and statistical data of land use, the carbon emission coefficient method was used to investigate the spatial characteristics of land use carbon emission of each district and county in Gansu Province in recent 20 years from the perspective of carbon ecological support coefficient and per capita carbon footprint. The main results are as follows: (1) the growth of land use carbon emissions in Gansu Province from 2000 to 2020 was significant, but the growth of carbon emissions after 2010 was fast, and the growth of carbon sinks was relatively slow. (2) The ecological support coefficient of carbon emissions at county level in Gansu Province showed a trend of high in the south and low in the north, high in the east and low in the west, and this trend became more and more obvious with the passage of time. (3) Based on carbon emission, county population, and carbon ecological support capacity, the per capita carbon footprint of each county in Gansu Province was analyzed. The results showed that the per capita carbon footprint in Gansu Province was increasing, indicating that the gap between carbon emission and carbon absorption in each county was widening. By the above result, the author divides the counties of Gansu Province into three regions, low-carbon maintenance area, green development area, and ecological optimization area, and puts forward development suggestions for different regions, respectively. Therefore, this paper can also provide a theoretical reference for the formulation of carbon neutral planning measures in inland northwest China.

Characteristics of carbon budget based on energy carbon emissions and vegetation carbon absorption.

How to evaluate the change characteristics of energy carbon emissions (ECE) and vegetation carbon absorption (VCA) by scientific methods is particularly important for achieving carbon peak by 2030 and carbon neutrality by 2060. Based on provincial-level energy consumption data, nighttime light data, and population data, this study realized spatial simulation of energy carbon emissions and analyzed the change characteristics of energy carbon emissions (ECE) and vegetation carbon absorption (VCA) combined with the net primary productivity (NPP)of vegetation. Besides, the relationship between energy carbon emissions, vegetation carbon absorption, and economic development was also analyzed at an urban scale. The results showed that (1) the total ECE increased from 4.34 billion tons in 2000 to 14.43 billion tons in 2019, but the growth rate of ECE decreased from 15.9% during 2000-2010 to 3.1% during 2010-2019. The VCA capacity has been increasing year by year. In 2019, it could absorb 1.56 billion tons more carbon dioxide than in 2000 with an increase of 16.1%. (2) Through the identification of the increasing and decreasing regions of ECE and VCA, it was found that the continuous rise area of ECE accounts for 0.5% of the study area; the area of fluctuating rise accounted for 6.7% of the study area. The area of continuous decline of VCA accounted for 0.2% of the study area; the area of fluctuating decline accounted for 49.6% of the study area. (3) The eastern China accounted for 42% of ECE and 17% of VCA with 11.4% of land, while the western region accounted for 26% of ECE and 55% of VCA with 66.6% of land, which indicated that there were significant differences in the characteristics of carbon budget between the eastern China and the western region. (4) The carbon pressure index (CPI) of most cities was on the rise, but the carbon efficiency index (CEI) was also on the rise, and cities were developing towards the model of low energy consumption and high output value. In a word, the growth rate of ECE is slowing down, and the VCA capacity is increasing. In the process of promoting carbon neutrality, we should be aware of the different resource endowments of different regions, realize the actual role of each region in carbon neutrality and economic development, and allocate carbon neutrality tasks differently.

Analysis of spatial and temporal changes in human interference in important ecological function areas in China: the Gansu section of Qilian Mountain National Park as an example.

The disturbance characteristics and driving factors of human activity intensity in national parks are important factors affecting environmental change in ecological function areas. In-depth analysis of these must be the basis of improving the ecological environment in northwest China. This study selected data related to human activities from 2000 to 2020 to analyze the comprehensive impact of human interference on national park development and found that the NDVI (Normalized Difference Vegetation Index) of Qilian Mountain National Park showed an increasing trend and that the NPP (net primary productivity) showed spatial distribution characteristics of decreasing from east to west during the study period. This showed that human interference in and around the national park was changing significantly and that the high value area was gradually shifting southward. In the first decade, economic and social development was slow; related industries such as industry, tourism, and modern agriculture were not introduced on a large scale; and the ecological environment was in relatively good condition, with relatively weak human interference. However, in the second decade, human interference was prominent, with deeper ecological damage, but rapid economic development. Infrastructure development, population urbanization, and traditional production and living practices were the main factors driving changes in human interference. The Chinese government's proposed green building policy will further reduce the ecological impact of human activities while ensuring economic development. Building upon this, the present paper puts forth a "zero-disturbance" framework for national parks, aiming to offer recommendations for the future development of such parks.

Resilience or efficiency? Strategic options for sustainable development of agricultural systems in ecologically fragile areas of China.

Sustainable development of agricultural systems is crucial for ensuring global food security, and resilience and efficiency are important topics for sustainable development of agricultural systems. Therefore, it is important to study the coupling and coordination relationship between agricultural system resilience and agricultural production efficiency, and explore the sustainable development model of agricultural system accordingly. Using statistical data from 2000 to 2020, we constructed a system of indicators for sustainable development of agricultural systems, and assessed the coordination status and interaction of agricultural system resilience and agricultural production efficiency in 49 county-level administrative units in the Loess Hilly Region Gansu Section (LHRGS) of China with the help of the coupling coordination degree (CCD) model, bivariate Moran's I index, and geographically weighted regression (GWR) model. The results show as follows: (1) The level of resilience of the LHRGS agricultural system and the level of agricultural production efficiency shows a continuous upward trend and a robust growth state. (2) High-value areas of the LHRGS agricultural system resilience are concentrated in counties with better resource endowment, and high-value areas of agricultural production efficiency are distributed in regions with stronger innovation capacity, and there is a moderate level of coupling relationship between them. (3) The sustainable development capacity of the agricultural system is gradually improving, but there is a certain degree of heterogeneity between agricultural system resilience and agricultural production efficiency. (4) Agricultural input factors have significant effects on the sustainable development of the agricultural systems, and significant spatial differences are found in the effects of different agricultural input factors on the sustainable development of agricultural systems. Based on the findings of this study, policy recommendations for the sustainable development of agricultural systems in ecologically fragile areas are proposed.

Green means go: Green light promotes hypocotyl elongation via brassinosteroid signaling.

Although many studies have elucidated the mechanisms by which different wavelengths of light (blue, red, far-red, or ultraviolet-B [UV-B]) regulate plant development, whether and how green light regulates plant development remains largely unknown. Previous studies reported that green light participates in regulating growth and development in land plants, but these studies have reported conflicting results, likely due to technical problems. For example, commercial green light-emitting diode light sources emit a little blue or red light. Here, using a pure green light source, we determined that unlike blue, red, far-red, or UV-B light, which inhibits hypocotyl elongation, green light promotes hypocotyl elongation in Arabidopsis thaliana and several other plants during the first 2-3 d after planting. Phytochromes, cryptochromes, and other known photoreceptors do not mediate green-light-promoted hypocotyl elongation, but the brassinosteroid (BR) signaling pathway is involved in this process. Green light promotes the DNA binding activity of BRI1-EMS-SUPPRESSOR 1 (BES1), a master transcription factor of the BR pathway, thus regulating gene transcription to promote hypocotyl elongation. Our results indicate that pure green light promotes elongation via BR signaling and acts as a shade signal to enable plants to adapt their development to a green-light-dominant environment under a canopy.

Trade for Food Security: The Stability of Global Agricultural Trade Networks.

Global food production is facing increasing uncertainties under climate change and the coronavirus pandemic, provoking challenges and severe concerns to national food security. The role of global agricultural trade in bridging the imbalance between food supply and demand has come to the fore. However, the impact of multifaceted and dynamic factors, such as trade policies, national relations, and epidemics, on the stability of the agricultural trade network (ATN) needs to be better addressed. Quantitatively, this study estimated grouping characteristics and network stability by analyzing the changing global ATN from 1986 to 2018. We found that the evolution of global agricultural trade communities has gone through four stages: the dominance of the US-Asian community, the rise of the European-African community, the formation of tri-pillar communities, and the development of a multipolar community with a more complex structure. Despite witnessing a progressive increase in the nodal stability of the global ATN during the decades, particular gaps can still be found in stability across countries. Specifically, the European community achieved stability of 0.49 and its trade relations were effectively secured. Meanwhile, the remaining leading communities' stability shows a stable and upward trend, albeit with more significant challenges in trade relations among some of them. Therefore, how to guarantee the stability of trade relations and strengthen the global ATN to resist external shocks has become an essential question to safeguard global food security.

Agricultural Eco-Efficiency Response and Its Influencing Factors from the Perspective of Rural Population Outflowing: A Case Study in Qinan County, China.

Agriculture is the source of human clothing and food, but it also brings negative externalities to the environment. The outflow of the rural population is one of the factors for changes in the characteristics of the rural population. Farmers' decisions on agricultural production can affect agricultural ecological efficiency. Therefore, it is necessary to study the relationship between the two in rural development. Taking Qin'an County in the Loess Hilly Region of central Gansu, China, as an example, this paper analyzed the demographic characteristics and the evolution characteristics of agricultural eco-efficiency under the background of rural population outflowing, and the impact of the former on the latter, based on the panel statistical data of 17 villages and towns from 2001 to 2020. The results show that (1) From 2001 to 2020, the non-agricultural level of Qin'an County's labor force showed an upward fluctuation trend. The level of aging was relatively stable, and the per capita disposable income was significantly increased. (2) From 2001 to 2020, the agricultural eco-efficiency of Qin'an County showed a wavy change, but there were some towns and villages that have not been effectively developed. The regional differences are significantly different. (3) The non-agriculturalization level of the labor force promotes agricultural eco-efficiency through the direct effect rather than the space spillover effect. The positive effect of aging on agricultural eco-efficiency was mainly reflected through direct effect rather than spatial spillover effect. Per capita, disposable income has a significant positive spatial spillover effect on agricultural eco-efficiency. Finally, this paper provides a scientific reference for promoting the improvement of agricultural eco-efficiency and sustainable development. This is of great theoretical and practical significance for the realization of rural revitalization.

CRY2 interacts with CIS1 to regulate thermosensory flowering via FLM alternative splicing.

Cryptochromes (CRYs) are evolutionarily conserved photolyase-like photoreceptors found in almost all species, including mammals. CRYs regulate transcription by modulating the activity of several transcription factors, but whether and how they affect pre-mRNA processing are unknown. Photoperiod and temperature are closely associated seasonal cues that influence reproductive timing in plants. CRYs mediate photoperiod-responsive floral initiation, but it is largely unknown whether and how they are also involved in thermosensory flowering. We establish here that blue light and CRY2 play critical roles in thermosensory flowering in Arabidopsis thaliana by regulating RNA alternative splicing (AS) to affect protein expression and development. CRY2 INTERACTING SPLICING FACTOR 1 (CIS1) interacts with CRY2 in a blue light-dependent manner and promotes CRY2-mediated thermosensory flowering. Blue light, CRYs, and CISs affect transcriptome-wide AS profiles, including those of FLOWERING LOCUS M (FLM), which is critical for temperature modulation of flowering. Moreover, CIS1 binds to the FLM pre-mRNA to regulate its AS, while CRY2 regulates the RNA-binding activity of CIS1. Thus, blue light regulates thermosensory flowering via a CRY2-CIS1-FLM signaling pathway that links flowering responses to both light and ambient temperature.

Reconstruction and application of the temperature-vegetation-precipitation drought index in mainland China based on remote sensing datasets and a spatial distance model.

In recent years, remote sensing drought monitoring indices have been gradually developed and have been widely used for global or regional drought monitoring due to their strong drought-monitoring capabilities and easy implementation advantages. However, some defects of remote sensing drought indices stand to be improved due to certain errors in the inversion of surface characteristics by remote sensing datasets. The temperature-vegetation-precipitation drought index (TVPDI) was taken as the research object, and the leaf area index (LAI), the difference between the land surface temperature (LST) and monthly average temperature, and Global Precipitation Measurement (GPM) precipitation data were selected instead of the normalized difference vegetation index (NDVI), LST and tropical rainfall measuring mission (TRMM) data to improve TVPDI. The improved remote sensing drought index was named the improved temperature-vegetation-precipitation drought index (iTVPDI). The drought-monitoring accuracy of iTVPDI was verified by the gross primary productivity (GPP), soil moisture, and crop yield per unit. The drought-monitoring ability of iTVPDI was verified with traditional drought indices, including the standardized precipitation index (SPI), standardized precipitation evapotranspiration index (SPEI), Palmer drought severity index (PDSI), temperature-vegetation drought index (TVDI), drought severity index (DSI) and crop water stress index (CWSI). The drought-monitoring accuracy of iTVPDI was verified by selecting sample areas. iTVPDI was applied to monitor drought in mainland China over the 2001-2020 period and obtained four main results. First, the correlation analyses of iTVPDI and TVPDI with GPP, crop yield per unit area, and soil moisture showed that iTVPDI had a stronger monitoring ability in Northeast, North, and Southwest China; the R2 value obtained with soil moisture was 0.62 (p < 0.05), and this value was higher than that of TVPDI. Then, the correlation analyses of iTVPDI and TVPDI with SPI, SPEI, PDSI, CWSI, DSI and TVDI showed that the correlation coefficients of iTVPDI and TVPDI with these six indicators were basically consistent, which indicated that the drought-monitoring capability of iTVPDI was consistent with that of TVPDI. In local areas such as the Qinghai-Tibet Plateau in China, the monitoring ability of iTVPDI was stronger than that of TVPDI. Third, through the sample area analysis, iTVPDI was found to moderate the NDVI-characterized vegetation factors in TVPDI in low-vegetation-cover areas affected by soil disturbances and in high-vegetation-cover areas affected by oversaturation. Finally, the results obtained from the application of iTVPDI in mainland China showed that during the warm-dry to warm-wet climate transition between 2001 and 2021, in 2010 and 2018, and in other special drought years, iTVPDI had the best response.

Differentiation and correlation of spatial pattern and multifunction in rural settlements considering topographic gradients: Evidence from Loess Hilly Region, China.

In the process of rapid industrialization and urbanization, China's rural settlements are undergoing rapid differentiation and reorganization. Their spatial pattern and multifunction have attracted much attention. In the Loess Hilly Region of China, topographic factors are deeply involved in the formation and evolution of the spatial pattern and multifunction in rural settlements. Therefore, this paper proposed a new method of topographic gradient analysis based on micro-geomorphic units. Taking Tianshui City in Longzhong Loess Hilly Region as an example, we analyzed the gradient differentiation and spatial correlation of the spatial pattern and multifunction in rural settlements. The results indicated that: (1) The topographic gradient differentiation of spatial pattern in rural settlements was distinct. As the topographic gradients rose, the numerical distributions of TA, AREA_CV, MPI, PR, and SHDI were generally concentrated from high to low values. The numerical distribution of LFI was generally scattered from low to high values. In addition, the numerical distribution of AWMSI and AWMPFD showed the "arch bridge" pattern. (2) The topographic gradient differentiation of multifunction in rural settlements was distinct. The overall level of LF was relatively low, and the numerical difference was small. It had the characteristics of concentrated distribution and marginal distribution in geographical space. The overall level of PF was low, and the spatial distribution had strong urban directivity and significant topographic gradient differences. The overall level of EF was relatively low, and the spatial distribution had significant horizontal zonality and topographic gradient differences. (3) Rural settlements' scale, distribution, and structure were generally synergistic with LF and PF, but there were trade-off relationships with EF. Moreover, the trade-off/synergy relationships between spatial pattern and multifunction had significant spatial heterogeneity in terms of spatial distribution. This paper is significant for formulating settlement development and construction plans, guiding spatial reconstruction and functional reorganization, improving settlement living environment, and promoting rural revitalization.

Light-Response Bric-A-Brack/Tramtrack/Broad proteins mediate cryptochrome 2 degradation in response to low ambient temperature.

Cryptochromes (crys) are photolyase-like blue-light receptors first discovered in Arabidopsis thaliana and later identified in all major evolutionary lineages. Crys are involved in not only blue light responses but also in temperature responses; however, whether and how cry protein stability is regulated by temperature remains unknown. Here, we show that cry2 protein abundance is modulated by ambient temperature and cry2 protein is degraded under low ambient temperature via the 26S proteasome. Consistent with this, cry2 shows high levels of ubiquitination under low ambient temperatures. Interestingly, cry2 degradation at low ambient temperatures occurs only under blue light and not under red light or dark conditions, indicating blue-light-dependent degradation of cry2 at low ambient temperature. Furthermore, low ambient temperature promotes physical interaction of Light-Response Bric-a-Brack/Tramtrack/Broad (LRB) proteins with cry2 to modulate its ubiquitination and protein stability in response to ambient temperature. LRBs promote high-temperature-induced hypocotyl elongation by modulating the protein stability of cry2 protein. These results indicate that cry2 accumulation is regulated by not only blue light but also ambient temperature, and LRBs are responsible for cry2 degradation at low ambient temperature. The stabilization of cry2 by high temperature makes cry2 a better negative regulator of temperature responses.

The spatial differentiation of quality of rural life based on natural controlling factors: A case study of Gansu Province, China.

The laws of regional differentiation of county development and influencing factors on the quality of rural life (QRL), affect not only the vital interests of rural residents but also the scientific implementation of rural revitalization strategy. In this paper, taking 87 counties (cities, districts) of Gansu Province as the region of study, we constructed five-dimensional model of QRL index. Then, Pearson correlation, spatial coupling, geographical detector and tradeoff analysis methods were used to analyze the QRL's spatial differentiation and quantitively identify its natural controlling factors. Further, we discussed the mechanism of spatial differentiation of QRL in Gansu Province and provided recommendations for improving QRL. The results show that: (1) QRL in Gansu Province is characterized by spatial heterogeneity and agglomeration, and decreases from west to east. There are five hot spots and four cold spots of QRL. (2) Altitude, slope, precipitation, and distance to the provincial capital (DTTPC) are the natural controlling factors of spatial differentiation of QRL in Gansu Province. Their influences are quantified to be 0.19, 0.37, 0.37 and 0.20, respectively. (3) The tradeoff between QRL and precipitation is the strongest, with root mean square deviation (RMSD) of 0.293. The tradeoff between QRL and altitude/slope/DTTCC are of medium level and decrease successively, with values of 0.238, 0.255 and 0.2 respectively. (4) According to the different influences of natural controlling factors on QRL, Gansu Province was classified into three regional types: natural environment restricted type, resource abundance restricted type and economic location restricted type. Thus, we can improve the QRL on the basis of identifying driving mechanisms in different regions, make policies according to local conditions, and further promote the rural development.

Identifying key landscape pattern indices influencing the ecological security of inland river basin: The middle and lower reaches of Shule River Basin as an example.

Landscape pattern evolution leads to changes of landscape spatial structure, which are intuitively reflected in the changes of ecosystem structure and composition and finally affect ecological security. In this paper, we assessed the spatiotemporal variation of the ecological security and landscape pattern of the middle and lower reaches of Shule River Basin in 1987-2015. Further, we analyzed the correlation between the ecological security and landscape pattern of the study region and correlation coefficients were calculated. On this basis, the key landscape pattern indices influencing the ecological security of the study region were identified. This may provide useful information for ecological regulation and design. The results show that: (1) From 1987 to 2015, the ecological security in the middle and lower reaches of the Shule River Basin was of medium or low level, showing periodic "U" shaped fluctuations, and the fluctuation period was gradually shortened. In addition, there was an overall spatial pattern of "high ecological security in the west, middle and south and low ecological security in the east". (2) The landscape pattern showed clear stage characteristics. The complexity of landscape pattern increased from 1987 to 1996 and decreased after 1996. (3) Landscape size, shape, quantity, type and spatial configuration had important impacts on ecological security and showed significant temporal variation. In a period when the influence of human activities was weak, ecological security was mainly related to landscape area indices. With increase in human activities, landscape shape, fragmentation and connectivity changed greatly, which led to changes in the structure and composition of ecosystem, thus finally affecting ecological security.

Farmers' Rural-To-Urban Migration, Influencing Factors and Development Framework: A Case Study of Sihe Village of Gansu, China.

Farmers are the major participants in rural development process and their willingness to settle in urban areas directly affects the implementation of rural revitalization strategy. Based on Ostrom's institutional analysis and development (IAD) framework, we analyzed farmers' willingness to settle in urban areas and its influencing factors by binary Logistic regression and cluster analysis of survey data of 190 rural households in Sihe village of Gansu Province of China. The results show that: (1) In Sihe village, farmers' willingness to settle in urban areas was low in general and influenced by their neighbors' decisions or behaviors. Households willing and unwilling to migrate to urban areas both presented significant spatial agglomeration. (2) The factors influencing farmers' willingness to settle in urban areas were analyzed from six aspects: individual characteristics, family characteristics, residence characteristics, cognitive characteristics, institutions, and constraints. The main influencing factors were found to be age, occupation, number of non-agricultural workers in the family, household cultivated land area, annual household income, house building materials, degree of satisfaction with social pension, homestead and contracted land subsidies, income constraints, and other constraints. (3) Individual heterogeneity and difference in economic basis determined the difference in farmers' willingness to settle in urban areas. Institutions and constraints played different roles in the migration willingness of different groups of farmers (Note: More details on the sample as well as further interpretation and discussion of the surveys are available in the associated research article ("Village-Scale Livelihood Change and the Response of Rural Settlement Land Use: Sihe Village of Tongwei County in Mid-Gansu Loess Hilly Region as an Example" (Ma, L.B.; Liu, S.C.; Niu, Y.W.; Chen, M.M., 2018)).

Village-Scale Livelihood Change and the Response of Rural Settlement Land Use: Sihe Village of Tongwei County in Mid-Gansu Loess Hilly Region as an Example.

Rural livelihood change has great influence on the scale, structure, and morphology of rural settlement land use, thus bringing new challenges to rural revitalization and settlement reconstruction. Sihe village of Tongwei County in mid-Gansu loess hilly region (China) was taken as an example here. Based on participatory rural appraisal data, we analyzed the structure and allocation of rural households' livelihood assets as well as their livelihood diversity by using ecological asset, livelihood diversification index, and landscape pattern index models. We aimed to find a response mechanism between rural livelihood change and rural settlement land use change. The results might provide useful information for the selection of new village sites, reconstruction of rural settlements, and creation of livable rural environment. Results indicate that: (1) The total value of the average livelihood assets per household in the Sihe village increased significantly from 0.48 in 1988 to 1.288 in 2016. The four types of livelihood assets including natural, material, manpower, and financial assets changed with time. In 1988, the manpower asset was the most important type of livelihood assets, with value accounting for 76.67% of the total value of livelihood assets. With the extension of time, the proportions of the four types of assets in total livelihood assets became closer to each other. The livelihood diversification index of the Sihe village increased from 2.01 in 1988 to 3 in 2016, indicating the rural livelihoods became diverse; (2) Because of the dual influence of external environmental factors and the rural development policies of the country and the region, the livelihoods changed towards agricultural sector from 1988 to 2008, and the agricultural livelihoods tended to be diverse. The following trend of livelihood strategy change was observed: from diverse non-agricultural production group (IV) to agricultural and non-agricultural production group (III), then to diverse agricultural production group (II) and finally to agricultural production group (I). After 2008, the livelihoods changed towards non-agricultural sector, and the non-agricultural livelihoods tended to be diverse. This trend of livelihood change is opposite to that before 2008; (3) 2008 is the key year of livelihood change. Livelihood change caused changes in the scale, structure, and morphology of rural settlement land use, which eventually led to the change of rural residential land use.

UVR8 Interacts with BES1 and BIM1 to Regulate Transcription and Photomorphogenesis in Arabidopsis.

UV-B light (UV-B radiation) is known to inhibit plant growth, but the mechanism is not well understood. UVR8 (UV RESISTANCE LOCUS 8) is a UV-B light photoreceptor that mediates UV-B light responses in plants. We report here that UV-B inhibits plant growth by repressing plant steroid hormone brassinosteroid (BR)-promoted plant growth. UVR8 physically interacts with the functional dephosphorylated BES1 (BRI1-EMS-SUPPRESSOR1) and BIM1 (BES1-INTERACTING MYC-LIKE 1) transcription factors that mediate BR-regulated gene expression and plant growth to inhibit their activities. Genome-wide gene expression analysis defined a BES1-dependent UV-B-regulated transcriptome, which is enriched with genes involved in cell elongation and plant growth. We further showed that UV-B-activated and nucleus-localized UVR8 inhibited the DNA-binding activities of BES1/BIM1 to directly regulate transcription of growth-related genes. Our results therefore establish that UVR8-BES1/BIM1 interaction represents an early photoreceptor signaling mechanism in plants and serves as an important module integrating light and BR signaling.