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Seed size is controlled not only by intrinsic genetic factors but also by external environmental signals. Here, we report a major quantitative trait locus (QTL) gene for seed size and weight on chromosome 1 (SSW1) in Arabidopsis , and we found SSW1 acts maternally to positively regulate seed size. Natural variation in SSW1 contains three types of alleles. The SSW1 Cvi allele produces larger seeds with more amino acid and storage protein contents than the SSW1 Ler allele. SSW1Cvi displays higher capacity for amino acid transport than SSW1L er due to the differences in transport efficiency. Under low nitrogen supply, the SSW1 Cvi allele exhibits increased seed yield and nitrogen use efficiency (NUE). Locations of natural variation alleles of SSW1 are associated with local soil nitrogen contents, suggesting that SSW1 might contribute to geographical adaptation in Arabidopsis. Thus, our findings reveal a mechanism that coordinates seed growth and NUE, suggesting a potential target for improving seed yield and NUE in crops. [Display omitted] • SSW1 is the major QTL gene for seed size and weight on chromosome 1 in Arabidopsis • SSW1 encodes AAP8 and acts maternally to positively regulate seed size • Natural variation in SSW1 coordinates seed growth and NUE • Locations of natural alleles of SSW1 are associated with local soil nitrogen contents Jiang et al. report a major QTL gene for seed size and weight on chromosome 1 (SSW1) in Arabidopsis and found SSW1 acts maternally to positively regulate seed size. Natural allelic variation in SSW1 coordinates seed growth and NUE, providing a predominant gene for breeding high-yield and NUE crops. [ABSTRACT FROM AUTHOR]

Regardless of the implementation of central environmental protection inspection, a campaign style enforcement, across China to address the upsurging environmental issues in recent years, very few studies have revealed the effect of central environmental protection inspection on corporate environmental actions in China. This paper focuses on China's central environmental protection inspection to evaluate the effectiveness of campaign-style enforcement in promoting corporate environmental actions. Using a regression discontinuity design and one of the most comprehensive datasets of environmental statistics on firm-level pollution from 2011 to 2018 in one province in south China. Based on 15,154 enterprise observations, we find that the central environmental protection inspection is associated with substantial changes in corporate environmental actions. We also find that the number of polluting firms shrank by 48% (and by even more among small and micro firms) after the implementation of the central environmental protection inspection. Furthermore, the central environmental protection inspection significantly reduces industrial chemical oxygen demand (COD) emissions by at least 46.5% without affecting the production output of surviving firms. These findings are robust to alternative specifications and different sampling strategies. This paper opens up a new viewpoint to focus on the effect of the central environmental protection inspection on corporate environmental actions. The available evidence leads us to cautiously conclude that environmental campaign-style enforcement promotes firms meeting emissions reduction goals in the short term through end-of-pipe abatement. A long-term inspection mechanism and incentives for firms to carry out green transformations are thus recommended for future practice. Image 1 • The Central Environmental Protection Inspection has caused a large number of polluting firms to be closed. • The surviving polluting firms reduce pollutant by carrying out end-of-pipe emission reduction. • Campaign-style enforcement can improve the corporate environmental performance in the short term. • In the long run, effective supporting policies should be employed to guide firms to achieve green transformations. [ABSTRACT FROM AUTHOR]