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Rice XA21 is an immune receptor kinase that confers broad-spectrum resistance against Xanthomonas oryzaepv. oryzae(Xoo). Pathogenesis-related (PR) proteins are located downstream of the plant immune system and OsPR1A can be induced by Xoo. In this study, it was found that the OsPR1A protein was concentrated in the lesion region in rice leaves and barely detectable in the Xoo-free regions. The OsPR1A protein was detectable at 2 days post-inoculation (dpi) in 4021. In contrast, the expression of OsPR1A protein was detectable at 8 dpi in TP309. It indicated that the rapid induction of OsPR1A expression in 4021 is crucial for disease resistance. To investigate the function of OsPR1A protein in Xa21-mediated resistance, an RNA interference construct was transformed into 4021. The lesion lengths of OsPR1a-RNAi lines were shorter than that of TP309 and longer than that of 4021. OsPR1a-RNAi lines showed reduced OsPR1A abundance, in correlation with the compromised resistance to Xoo, supporting that OsPR1A play a positive role for Xa21-mediated resistance. These results enhance our understanding regarding the mechanism of Xa21-mediated resistance and the function of the OsPR1agene.

The intermolecular alkene 1,2-diarylation provides straightforward access to polyarylalkanes but suffers from substrate limitation, requiring directing auxiliaries or prefunctionalized aryl components. Herein, we report the development of a photocatalytic strategy that enables a three-component 1,2-diarylation of alkenes under mild reductive conditions using simple tertiary alkylamine as the terminal reductant. Readily accessible aryl iodides and cyanides serve as the C(sp2) electrophiles to simultaneously install two different aryl moieties across the olefins with high regioselectivity. This protocol exhibits a broad substrate scope for all of aryl, heteroatom-substituted, and even unactivated alkenes and can be easily scaled up to the gram-scale. Mechanistic studies reveal a halogen-atom transfer (XAT) of aryl iodides to transient aryl radicals while a single-electron transfer (SET) of aryl cyanides to persistent aryl radical anions, both allowing for a regiocontrollable radical relay sequence.

Herein, a facile and efficient dehalogenative arylation of unactivated alkyl halides enabled by electrochemical reductive coupling is developed, affording a series of C(sp2)–C(sp3) products in moderate to good yields. This protocol proceeds in the absence of transition metal catalysts and redox mediators. The reaction features mild conditions, broad substrate scope, and high tolerance of functional groups and is demonstrated to be applicable for gram-scale synthesis and late-stage functionalization of natural products.