Nitrogen (N) and carbon (C) are essential elements for plant growth and crop yield. Thus, improved N and C utilisation contributes to agricultural productivity and reduces the need for fertilisation. In the present study, we find that overexpression of a single rice gene, Oryza sativa plasma membrane (PM) H⁺-ATPase 1 (OSA1), facilitates ammonium absorption and assimilation in roots and enhanced light-induced stomatal opening with higher photosynthesis rate in leaves. As a result, OSA1 overexpression in rice plants causes a 33% increase in grain yield and a 46% increase in N use efficiency overall. As PM H⁺-ATPase is highly conserved in plants, these findings indicate that the manipulation of PM H⁺-ATPase could cooperatively improve N and C utilisation, potentially providing a vital tool for food security and sustainable agriculture.

Significance: Fungal disease is a major threat to agriculture and consequently human nutrition. Many pathogenic fungi penetrate through stomata. This study reveals that chitin oligosaccharide (CTOS) from fungal cell wall induces stomatal closure through its receptor CERK1, Ca ²⁺ , and S-type anion channel SLAC1, which would prevent fungal penetration. It is also shown that conversion of CTOS to chitosan oligosaccharide (CSOS) is a possible fungal strategy to circumvent stomatal immunity. At higher concentration, guard cells perceive CSOS, resulting in guard cell death, which potentially contributes to plant defense halting fungal infection through stomata. The finding of active guard cell death represents a conceptual advance in understanding of stomatal immunity and would guide future research on guard cell–microbe interaction and crop protection.

Plants possess diverse cell types and intricate regulatory mechanisms to adapt to the ever-changing environment of nature. Various strategies have been employed to study cell types and their developmental progressions, including single-cell sequencing methods which provide high-dimensional catalogs to address biological concerns. In recent years, single-cell sequencing technologies in transcriptomics, epigenomics, proteomics, metabolomics, and spatial transcriptomics have been increasingly used in plant science to reveal intricate biological relationships at the single-cell level. However, the application of single-cell technologies to plants is more limited due to the challenges posed by cell structure. This review outlines the advancements in single-cell omics technologies, their implications in plant systems, future research applications, and the challenges of single-cell omics in plant systems.

Summary: Existing CRISPR/Cas12a‐based diagnostic platforms offer accurate and vigorous monitoring of nucleic acid targets, but have the potential to be further optimized for more efficient detection. Here, we profiled 16 Cas12a orthologs, focusing on their trans‐cleavage activity and their potential as diagnostic enzymes. We observed the Mb2Cas12a has more robust trans‐cleavage activity than other orthologs, especially at lower temperatures. An engineered Mb2Cas12a‐RRVRR variant presented robust trans‐cleavage activity and looser PAM constraints. Moreover, we found the existing one‐pot assay, which simultaneously performed Recombinase Polymerase Amplification (RPA) and Cas12a reaction in one system, resulted in the loss of single‐base discrimination during diagnosis. Therefore, we designed a reaction vessel that physically separated the RPA and Cas12a steps while maintaining a closed system. This isolated but closed system made diagnostics more sensitive and specific and effectively prevented contamination. This shelved Mb2Cas12a‐RRVRR variant‐mediated assay detected various targets in less than 15 min and exhibited equal or greater sensitivity than qPCR when detecting bacterial pathogens, plant RNA viruses and genetically modified crops. Overall, our findings further improved the efficiency of the current CRISPR‐based diagnostic system and undoubtedly have great potential for highly sensitive and specific detection of multiple sample types.

Stomatal pores in the plant epidermis open and close to regulate gas exchange between leaves and the atmosphere. Upon light stimulation, the plasma membrane (PM) H⁺-ATPase is phosphorylated and activated via an intracellular signal transduction pathway in stomatal guard cells, providing a primary driving force for the opening movement. To uncover and manipulate this stomatal opening pathway, we screened a chemical library and identified benzyl isothiocyanate (BITC), a Brassicales-specific metabolite, as a potent stomatal-opening inhibitor that suppresses PM H⁺-ATPase phosphorylation. We further developed BITC derivatives with multiple isothiocyanate groups (multi-ITCs), which demonstrate inhibitory activity on stomatal opening up to 66 times stronger, as well as a longer duration of the effect and negligible toxicity. The multi-ITC treatment inhibits plant leaf wilting in both short (1.5 h) and long-term (24 h) periods. Our research elucidates the biological function of BITC and its use as an agrochemical that confers drought tolerance on plants by suppressing stomatal opening.