10.1021/pr4009942.s003 Barbara Molesini Barbara Molesini Daniela Cecconi Daniela Cecconi Youry Pii Youry Pii Tiziana Pandolfini Tiziana Pandolfini Local and Systemic Proteomic Changes in <i>Medicago Truncatula</i> at an Early Phase of <i>Sinorhizobium meliloti</i> Infection American Chemical Society 2014 Sinorhizobium meliloti InfectionA sucrose synthase stress response alteration bacteria signal exchange root nodules induction formation biotic stress proteome changes rhizobial infection Systemic Proteomic Changes Medicago truncatula chloroplast proteins Sinorhizobium meliloti infection energy metabolism ABA redox enzymes Medicago Truncatula proteomic changes ascorbate peroxidase 2014-02-07 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Local_and_Systemic_Proteomic_Changes_in_i_Medicago_Truncatula_i_at_an_Early_Phase_of_i_Sinorhizobium_meliloti_i_Infection/2325901 A symbiotic association with N-fixing bacteria facilitates the growth of leguminous plants under nitrogen-limiting conditions. The establishment of the symbiosis requires signal exchange between the host and the bacterium, which leads to the formation of root nodules, inside which bacteria are hosted. The formation of nodules is controlled through local and systemic mechanisms, which involves root-shoot communication. Our study was aimed at investigating the proteomic changes occurring in shoots and concomitantly in roots of <i>Medicago truncatula</i> at an early stage of <i>Sinorhizobium meliloti</i> infection. The principal systemic effects consisted in alteration of chloroplast proteins, induction of proteins responsive to biotic stress, and changes in proteins involved in hormonal signaling and metabolism. The most relevant local effect was the induction of proteins involved in the utilization of photosynthates and C-consuming processes (such as sucrose synthase and fructose-bisphosphate aldolase). In addition, some redox enzymes such as peroxiredoxin and ascorbate peroxidase showed an altered abundance. The analysis of local and systemic proteome changes suggests the occurrence of a stress response in the shoots and the precocious alteration of energy metabolism in roots and shoots. Furthermore, our data indicate the possibility that ABA and ethylene participate in the communicative network between root and shoot in the control of rhizobial infection.