INCREASED SIZE EXCLUSION LIMIT 2 (ISE2) encodes a putative DEVIL-box RNA helkase originally identified through a genetic screening for Arabidopsis mutants altered in plasmodesmata (PD) aperture. Depletion of 1SE2 also affects chloroplasts activity, decreases accumulation of photosynthetic pigments and alters expression of photosynthetic genes. In this work, we show the chloroplast localization of ISE2 and decipher its role in plastidic RNA processing and, consequently, PD function. Group It intron-containing RNAs from chloroplasts exhibit defective splicing in ise2 mutants and /SE2-silenced plants, compromising plastid viability. Furthermore, RNA immunopredpitation suggests that ISE2 binds in vivo to several splicing-regulated RNAs. Finally, we show that the chloroplast elpr2 mutant (defective in a subunit of a plaslidic Clp protease) also exhibits abnormal PD function during embryogenesis, supporting the idea that chloroplast RNA processing is required to regulate cell cell communication in plants.