Photomorphogenic tomato mutants high-pigment 1 and aurea responses to iron deficiency

Iron (Fe) is a micronutrient for plant development, as constituent of several photosynthesis- and respiration-related proteins and enzymes. Consequently, Fe deficiency leads to chlorosis in leaves and plant growth impairment. It has become increasingly evident that light signals coordinate iron homeostasis in plants. To further address new insights into how light is a fundamental part of Fe deficiency responses, we employed Micro-Tom (wild type, WT) tomato (Solanum lycopersicum L.) plants and high-pigment 1 (hp1) and aurea (au) photomorphogenic mutants, which exhibit an excessive light response and low light perception, respectively. Plant growth, pigment contents, oxidative status, and nutrient profile were analyzed. The results revealed the influence of the different genotypes on Fe deficiency responses. WT and au exhibited plant growth reduction under Fe deficiency. WT, hp1 and au demonstrated that Fe availability and light perception play fundamental roles in chlorophyll and anthocyanin biosynthesis. Lipid peroxidation was not increased for any genotype under Fe deficiency, indicating that mutations in light perception and signaling differentially modulate H2O2 production and scavenging under this condition. Additionally, macronutrients and micronutrients were taken up and distributed differently among the different plant genotypes, tissues and Fe conditions analyzed. In general, the au plants accumulated lower amounts of nutrients (Ca, S, P, Mg, B and Zn) than the WT and hp1 genotypes regardless of the Fe concentrations. Our data clearly indicates that light perception and signaling influence Fe-dependent morphophysiological responses in plants, suggesting possibilities for biotechnological improvement of crops grown under Fe shortage.