Organ-Specific Epidermal Bladder Cell Contribution to Quinoa's Performance

Quinoa is a facultative halophyte capable of thriving in harsh environmental conditions. Its epidermal bladder cells (EBCs) have been suggested to play a key role in salinity tolerance. To clarify their importance, several experiments have been conducted to assess the effects of EBC removal. However, existing studies have yielded conflicting evidence, both supporting and rejecting their significance. Notably, most of these investigations have focused on leaf EBCs, despite the fact that quinoa accumulates more ions in the stem than in the leaves. To address this gap, we designed a manipulative experiment to remove EBCs from the leaves and stems. Our results demonstrate that stem EBCs is crucial under both saline and non-saline conditions. Their removal led to reduced growth and transpiration in non-saline environments and decreased shoot biomass and Na⁺ accumulation in the shoot under saline conditions, while the removal of leaf EBCs did not alter the growth under either non-saline or saline conditions. Based on these findings, we hypothesize that stem EBCs play a role in ion homeostasis and water movement.