Arabidopsis Arabidopsis Proteins Arabidopsis protein Biological Transport Cell-to-cell communication Chloroplast Chloroplasts DEAD box protein DEAD-box RNA Helicases Gene Expression Regulation, Plant Genes, Reporter INCREASED SIZE EXCLUSION LIMIT2 protein, Arabidopsis IgA Introns Mutation Photosynthesis Plants, Genetically Modified Plasmodesmata RNA RNA Helicases RNA Splicing RNA helicase RNA splicing RNA, Chloroplast Retrograde signals Seedlings TURBINAS cells and cell components chloroplast chloroplast RNA