Comparative transcriptome and physiological analyses reveal key factors in the tolerance of peach rootstocks to iron deficiency chlorosis.

Iron (Fe) deficiency chlorosis (IDC) is a major nutritional disorder in fruit trees grown on calcareous soils. As a peach rootstock, 'GF677' (Prunus dulcis Miller × P. persica (L.) Batsch) has great tolerance to Fe deficiency, but the molecular mechanisms of 'GF677' that support the process of iron deficiency chlorosis tolerance are still unknown. In this study, the key factors for differential iron deficiency chlorosis tolerance in two contrasting rootstocks (IDC-tolerant: 'GF677', IDC-susceptible: 'Maotao' (P. persica)) were investigated. 'GF677' exhibited greater Fe transfer and accumulation capacities when compared with 'Maotao', and the analysis of photosynthetic pigments, related precursors, and antioxidative enzyme activities further demonstrated that 'GF677' was more tolerant to IDC when compared with 'Maotao'. Furthermore, comparative transcriptome analysis revealed differential expression in many genes involved in iron transport and storage, and in photosynthesis recovery. These results suggest that the greater IDC tolerance of 'GF677' can be attributed to the greater expression of key genes related to specific Fe transporters, defense systems, photosynthetic recovery, and/or special proteins. [ABSTRACT FROM AUTHOR]