Involved in a special stress-induced plastid-to-vacuole protein trafficking pathway. Interacts with ATG8F in plastid bodies to subsequently enable their delivery to the vacuole by an autophagic pathway. Interacts with the plastid proteins APE1 and PSBS/NPQ4 and may recruit them as cargo into plastid bodies that may be recognized by the autophagy machinery for degradation in the vacuole. Involved in the alleviation of damage caused by salt stress during plant development, probably through its involvement in plastid-to-vacuole and ER-to-vacuole trafficking (PubMed:25281689). Plays a role in seed germination in response to exogenous abscisic acid (ABA) treatment (PubMed:22253227). Interacts with ATG8F (PubMed:22253227, PubMed:22580699). Interacts with ATG8H (PubMed:22580699). Interacts with APE1 and PSBS/NPQ4 (PubMed:25281689). Under favorable growth conditions, partially associated with the endoplasmic reticulum (ER) membrane network. Upon exposure to carbon starvation, mainly associated with newly identified spherical compartments that dynamically move along the ER network and reach the lytic vacuole (PubMed:22253227). Under carbon starvation, salt stress and during senescence, localized to novel plastid-associated bodies that are transported to vesicles. These plastid bodises are morphologically distinct from the ER-associated bodies (PubMed:25281689). By salt stress. Plants over-expressing ATI1 display increased ability of seed germination in presence of exogenous abscisic acid (ABA). Plants silencing ATI1 and ATI2 display decreased ability of seed germination in presence of exogenous ABA.