SlZIP11 mediates zinc accumulation and sugar storage in tomato fruits.

BACKGROUND

Zinc (Zn) is a vital micronutrient essential for plant growth and development. Transporter proteins of the ZRT/IRT-like protein (ZIP) family play crucial roles in maintaining Zn homeostasis. Although the acquisition, translocation, and intracellular transport of Zn are well understood in plant roots and leaves, the genes that regulate these pathways in fruits remain largely unexplored. In this study, we aimed to investigate the function of in regulating tomato fruit development.

METHODS

We used L. 'Micro-Tom' () is highly expressed in tomato fruit, particularly in mature green (MG) stages. For obtaining results, we employed reverse transcription-quantitative polymerase chain reaction (RT-qPCR), yeast two-hybrid assay, bimolecular fluorescent complementation, subcellular localization assay, virus-induced gene silencing (VIGS), overexpression, determination of Zn content, sugar extraction and content determination, and statistical analysis.

RESULTS

RT-qPCR analysis showed elevated expression in MG tomato fruits. expression was inhibited and induced by Zn deficiency and toxicity treatments, respectively. Silencing the VIGS technology resulted in a significant increase in the Zn content of tomato fruits. In contrast, overexpression of led to reduced Zn content in MG fruits. Moreover, both silencing and overexpression of caused alterations in the fructose and glucose contents of tomato fruits. Additionally, SlSWEEET7a interacted with SlZIP11. The heterodimerization between SlSWEET7a and SlZIP11 affected subcellular targeting, thereby increasing the amount of intracellularly localized oligomeric complexes. Overall, this study elucidates the role of SlZIP11 in mediating Zn accumulation and sugar transport during tomato fruit ripening. These findings underscore the significance of SlZIP11 in regulating Zn levels and sugar content, providing insights into its potential implications for plant physiology and agricultural practices.