A Stepwise Guide to the Isolation and Analysis of Leaf Surface and Apoplastic RNA Using Arabidopsis Rosettes.

The surface of plant leaves and intercellular space within leaves (the apoplast) serve as key interfaces for molecular exchange between plants and their interacting microbes. In previous work, we demonstrated the presence of a diverse range of RNA species in the apoplast of Arabidopsis rosettes. More recently, our findings revealed that Arabidopsis plants also actively secrete RNA onto their leaf surfaces.

Arabidopsis Produces Distinct Subpopulations of Extracellular Vesicles That Respond Differentially to Biotic Stress, Altering Growth and Infectivity of a Fungal Pathogen.

Extracellular vesicles (EVs) secreted by mammalian cells are highly heterogeneous in content and function. Whether this is also true for EVs secreted by plant cells is not yet known. To address this, we used high-resolution density gradient ultracentrifugation and total internal fluorescence microscopy (TIRF-M) to purify and distinguish distinct subpopulations of Arabidopsis EVs.

Extracellular RNA: mechanisms of secretion and potential functions.

Extracellular RNA (exRNA) has long been considered as cellular waste that plants can degrade and utilize to recycle nutrients. However, recent findings highlight the need to reconsider the biological significance of RNAs found outside of plant cells. A handful of studies suggest that the exRNA repertoire, which turns out to be an extremely heterogenous group of non-coding RNAs, comprises species as small as a dozen nucleotides to hundreds of nucleotides long.

Arabidopsis apoplastic fluid contains sRNA- and circular RNA-protein complexes that are located outside extracellular vesicles.

Previously, we have shown that apoplastic wash fluid (AWF) purified from Arabidopsis leaves contains small RNAs (sRNAs). To investigate whether these sRNAs are encapsulated inside extracellular vesicles (EVs), we treated EVs isolated from Arabidopsis leaves with the protease trypsin and RNase A, which should degrade RNAs located outside EVs but not those located inside. These analyses revealed that apoplastic RNAs are mostly located outside and are associated with proteins.

Proteases inhibitors-insensitive cysteine proteases allow Nezara viridula to feed on growing seeds of field-grown soybean.

The southern green stink bug, Nezara viridula is one of the primary soybean pests and causes significant economic losses around the world. In spite of the high proteases inhibitor (PI) levels, N. viridula can feed on developing seeds of field-grown soybean and reduce crop yields.