Genotypic Variation under Fe Deficiency Results in Rapid Changes in Protein Expressions and Genes Involved in Fe Metabolism and Antioxidant Mechanisms in Tomato Seedlings (Solanum lycopersicum L.)

To investigate Fe deficiency tolerance in tomato cultivars, quantification of proteins and genes involved in Fe metabolism and antioxidant mechanisms were performed in Roggusanmaru and Super Doterang. Fe deficiency (Moderate, low and -Fe) significantly decreased the biomass, total, and apoplastic Fe concentration of Roggusanmaru, while a slight variation was observed in Super Doterang cultivar. The quantity of important photosynthetic pigments wsuch as total chlorophyll and carotenoid contents significantly decreased in Roggusanmaru than Super Doterang cultivar. The total protein profile in leaves and roots determines that Super Doterang exhibited an optimal tolerance to Fe deficiency compared to Roggusanmaru cultivar. A reduction in expression of PSI (photosystem I), PSII (photosystem II) super-complexes and related thylakoid protein contents were detected in Roggusanmaru than Super Doterang cultivar. Moreover, the relative gene expression of SlPSI and SlPSII were well maintained in Super Doteran than Roggusanmaru cultivar. The relative expression of genes involved in Fe-transport (SlIRT1 and SlIRT2) and Fe(III) chelates reductase oxidase (SlFRO1) were relatively reduced in Roggusanmaru, while increased in Super Doterang cultivar under Fe deficient conditions. The H+-ATPase relative gene expression (SlAHA1) in roots were maintained in Super Doterang compared to Roggusanmaru. Furthermore, the gene expressions involved in antioxidant defense mechanisms (SlSOD, SlAPX and SlCAT) in leaves and roots showed that these genes were highly increased in Super Doterang, whereas decreased in Roggusanmaru cultivar under Fe deficiency. The present study suggested that Super Doterang is better tomato cultivar than Roggusanmaru for calcareous soils.