Unraveling the puzzle of phloem parenchyma transfer cell wall ingrowth.

For over 100 years, transfer cells have puzzled researchers. Many hypotheses have been proposed to explain the jigsaw-like cell wall ingrowths that characterize the transfer cells found in nearly every angiosperm. Wei et al. (2020) investigate the formation and implications of the hallmark cell wall ingrowths of Arabidopsis phloem parenchyma transfer cells (PPTCs) via an elegant combination of genetics and manipulating sucrose availability. In doing so, they shed new light on the role of sugar signaling and carbohydrate export in the development and function of this unique cell type.