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Genetically modified (GM) crops tolerant to glyphosate have delivered significant economic benefits in farm management. However, the evolution of glyphosate resistance in weeds due to prolonged intensive use of glyphosate poses a serious threat to this weed management system. It is highly desirable in China to deploy dual herbicide-tolerant corn at the very beginning of GM corn release to delay the development of weed resistance to herbicides. Here, we report the creation and characterization of a herbicide-tolerant corn event SCB-29 that expresses both cp4 epsps and bar genes. This transgenic maize is tolerant to glyphosate up to 3600 g a.e. ha−1 and glufosinate up to 3600 g a.i. ha−1, which are quadruple the recommended rates for the two herbicides, respectively. SCB-29 is an event with only a single copy of T-DNA inserted into chromosome 10 of the maize genome. An event-specific PCR detection method was established and three generations of SCB-29 were detected by event-specific PCR suggesting that the transgenes are stably integrated into the maize genome. Analysis of the expression levels of the transgenes among plants of multiple generations by enzyme-linked immunosorbent assays suggested that the expressions are stable over different generations. Moreover, the major agronomic performances of SCB-29 appear to be similar to those of non-transgenic maize, suggesting that SCB-29 is not likely to have yield drag. Therefore, SCB-29 is an excellent herbicide-tolerant candidate to be developed into a commercial herbicide tolerance transgenic event. [ABSTRACT FROM AUTHOR]

Collapsed sweet potato vines observed in Hangzhou fields in September 2019 were found to be due to Sclerotinia sclerotiorum based on its morphology and ITS rDNA sequence. Here, the chitinase gene chit42 from Trichoderma harzianum was introduced into Ipomoea batatas using Agrobacterium-mediated transformation to evaluate the effect against subsequent disease severity from S. sclerotiorum. PCR analysis detected the transgene in 23 transformants with a transformation efficiency of 5.1%. RT-PCR analysis showed transgene mRNA expression in all four selected lines harboring chit42. Enzymatic tests showed a significant increase in the activity of endochitinase in extracts from leaf tissues of chit42-transgenic 75-day sweet potato lines. Virulence of three genetically different isolates was markedly reduced on leaves of 75-day-old chit42-transgenic plants compared with the controls. To our knowledge, this is the first report of S. sclerotiorum on sweet potato plants in China. [ABSTRACT FROM AUTHOR]

• cphA gene from N. flagelliforme was successfully introduced to A. thaliana. • Transgenic plants have higher drought tolerance compared with wild-type plants. • cphA gene may contribute to drought tolerance of N. flagelliforme. Nostoc flagelliforme is a terrestrial cyanobacterium distributed in arid or semiarid steppes in western and northwestern China. Cyanophycin is synthesized by cyanophycin synthetase (CphA), which serves as a storage polymer for nitrogen, carbon, and energy in N. flagelliforme. In the present study, c phA (GenBank Accession No.: KX469292), an open reading frame (ORF) of 2706 bp encoding a protein of 901 amino acid residues, was cloned. We found that cyanophycin synthesis was promoted by the expression of cphA in E. coli. The function of the cphA gene in Arabidopsis thaliana under drought stress was investigated, and stable integration and expression of transgenes in transgenic lines were confirmed by PCR, Western blot, Southern blot, and real-time PCR analyses. The transcript abundance of cphA was markedly increased in transgenic A. thaliana compared with that in the untransformed plants. A subcellular localization assay confirmed that cphA protein was targeted to the cytoplasm. The survival rate was also significantly higher in cphA overexpression lines than that in untransformed plants under drought stress, which verified by drought tolerance assay of the transgenic plants. These findings highlight the potential importance of cphA in the drought tolerance of N. flagelliforme. [ABSTRACT FROM AUTHOR]