Downregulation of Zn-transporters along with Fe and redox imbalance causes growth and photosynthetic disturbance in Zn-deficient tomato

Zinc (Zn) deficiency hinders growth and development in tomato. This study unveils the responses of how Zn starvation affects physiological and molecular processes in tomato. Zn-sensitive tomato cultivar (cv. Ratan) was used for this study. The sprouted three-days homogeneous plantlets thereafter were transferred to the hydroponic solution at pH ۶.۰. Furthermore, ZnSO۴ has been used as follows۸: ۲.۰ μM (Zn-sufficient or control) and ۰.۰۱ μM (Zn-deficient). The selected plants were grown in a plastic container (۸ L) having ۳ plants/per in indoor growth. We opted for a completely randomized block design (CRBD) in plant cultivation. Three independent biological replications were considered for data analysis. Zn deficiency negatively affected the biomass, cellular integrity, and chlorophyll synthesis in tomato. Also, Zn deficiency decreased the maximum yield of PSII, photosynthesis performance index and dissipation energy per active reaction center, although the antenna size, trapping energy efficiency and electron transport flux were stable in Zn-starved leaves. Further, Zn shortage caused a substantial reduction in Zn and Fe concentrations in both roots and shoots along with decreased root Fe-reductase activity accompanied by the downregulation of Fe-regulated transporter ۱, Zn transporter-like (LOC۱۰۰۰۳۷۵۰۹), and Zn transporter (LOC۱۰۱۲۵۵۹۹۹) genes predicted to be localized in the root plasma membrane. The interactome partners of these Zn transporters are predominantly associated with root-specific metal transporter, ferric-chelate reductase, BHLH transcriptional regulator, and Zn metal ion transporters, suggesting that Zn homeostasis may be tightly linked to the Fe status along with BHLH transcription factor in Zn-deficient tomato. We also noticed elevated O۲.- and H۲O۲ due to Zn deficiency which was consistent with the inefficient antioxidant properties. These findings will be useful in the downstream approach to improve vegetable crops sensitive to Zn-deficiency.

کلیدواژه ها:

Nutrient elements ، redox status ، tomato ، Zn transporters