The WRKY-type transcription factors are involved in plant development and stress responses, but how the regulation of stress tolerance is related to plant development is largely unknown. GsWRKY20 was initially identified as a stress response gene using large-scale Glycine soja microarrays. Quantitative reverse transcription-PCR (qRT-PCR) showed that the expression of this gene was induced by abscisic acid (ABA), salt, cold, and drought. Overexpression of GsWRKY20 in Arabidopsis resulted in a decreased sensitivity to ABA during seed germination and early seedling growth. However, compared with the wild type, GsWRKY20 overexpression lines were more sensitive to ABA in stomatal closure, and exhibited a greater tolerance to drought stress, a decreased water loss rate, and a decreased stomatal density. Moreover, microarray and qRT-PCR assays showed that GsWRKY20 mediated ABA signalling by promoting the expression of negative regulators of ABA signalling, such as AtWRKY40, ABI1, and ABI2, while repressing the expression of the positive regulators of ABA, for example ABI5, ABI4, and ABF4. Interestingly, GsWRKY20 also positively regulates the expression of a group of wax biosynthetic genes. Further, evidence is provided to support that GsWRKY20 overexpression lines have more epicuticular wax crystals and a much thicker cuticle, which contribute to less chlorophyll leaching compared with the wild type. Taken together, the findings reveal an important role for GsWRKY20 in enhancing drought tolerance and regulating ABA signalling.

As an open artificial ecosystem, the development of a city requires the continuous input and output of material and energy, which is called urban metabolism, and includes catabolic (material-flow) and anabolic (material-accumulation) processes. Previous studies have focused on the catabolic and ignored the anabolic process due to data and technology problems. The combination of remote-sensing technology and high-resolution satellite images facilitates the estimation of cumulative material amounts in urban systems. This study focused on persistent accumulation, which is the metabolic response of urban land use/urban land expansion, building stock, and road stock to land-use changes. Building stock is an extremely cost-intensive and long-lived component of cumulative metabolism. The study measured building stocks of Jinchang, China’s nickel capital by using remote-sensing images and field-research data. The development of the built environment could be analyzed by comparing the stock of buildings on maps representing different time periods. The results indicated that material anabolism in Jinchang is a distance-dependent function, where the amounts and rates of material anabolism decrease with changes in distance to the central business district (CBD) and city administration center (CAC). The cumulative metabolic rate and cumulative total metabolism were observed to be increasing, however, the growth rate has decreased.

No abstract