https://www.selleckchem.com/products/AZD0530.html Abscission is triggered by multiple environmental and developmental cues, including endogenous plant hormones. KNOTTED-LIKE HOMEOBOX (KNOX) transcription factors (TFs) play an important role in controlling abscission in plants. However, the underlying molecular mechanism of KNOX TFs in abscission is largely unknown. Here, we identified LcKNAT1, a KNOTTED-LIKE FROM ARABIDOPSIS THALIANA1 (KNAT1)-like protein from litchi, which regulates abscission by modulating ethylene biosynthesis. LcKNAT1 is expressed in the fruit abscission zone (FAZ) and its expression decreases during fruitlet abscission. Furthermore, the expression of ethylene biosynthetic genes, LcACS1, LcACS7, and LcACO2, increases in FAZ, in parallel with the emission of ethylene in fruitlets. In vitro and in vivo assays revealed that LcKNAT1 inhibits the expression of LcACS/ACO genes by directly binding to their promoters. Moreover, ectopic expression of LcKNAT1 represses flower abscission in tomatoes. Transgenic plants expressing LcKNAT1 also showed consistently decreased expressions of ACS/ACO genes. Collectively, these results indicate that LcKNAT1 represses abscission via the negative regulation of ethylene biosynthesis. © The Author(s) 2020. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email journals.permissions@oup.com.INTRODUCTION Several observational studies have shown decreases in measured influenza vaccine effectiveness (mVE) during influenza seasons. One study found decreases of 6%-11% per month during the 2011-12 to 2014-15 seasons. These findings could indicate waning immunity but could also occur if vaccine effectiveness is stable and vaccine provides partial protection in all vaccinees ("leaky") rather than complete protection in a subset of vaccinees. Since it is not known whether influenza vaccine is leaky, we simulated the 2011-12 to 2014-15 influenza s