Seedling root system adaptation to water availability during maize domestication and global expansion.

The maize root system has been reshaped by indirect selection during global adaptation to new agricultural environments. In this study, we characterized the root systems of more than 9,000 global maize accessions and its wild relatives, defining the geographical signature and genomic basis of variation in seminal root number. We demonstrate that seminal root number has increased during maize domestication followed by a decrease in response to limited water availability in locally adapted varieties. By combining environmental and phenotypic association analyses with linkage mapping, we identified genes linking environmental variation and seminal root number. Functional characterization of the transcription factor ZmHb77 and in silico root modeling provides evidence that reshaping root system architecture by reducing the number of seminal roots and promoting lateral root density is beneficial for the resilience of maize seedlings to drought.

[Child Persecutor or Child Savior? The Impact of Trauma and Migration on a Mother's Ambivalence in Relation to her Child]. / Enfant persécuteur ou enfant sauveur ? Quand trauma et migration s'amalgament à l'ambivalence de la mère dans la relation à son bébé.

Objectives The objectives of this paper are to explore the impact of psychological trauma and migration on a mother's ambivalence regarding her relationship with her child and to explore the effect on the child's "continuity of being." Methods Literature on the ambivalence of mothers who have experienced trauma and migration is reviewed. The authors present the hypothesis that the presence of trauma and/or migration exacerbate the phenomenon of ambivalence and that it may impact early interactions in mother-infant dyads. The stories of three migrant dyads are presented to illustrate these processes. Results Pregnancy is a period of psychological and identity reorganisation during which a mother's ambivalence is as necessary as it is structuring for the child to come. The stories of the three mother-infant dyads presented in this paper highlight the impacts of migration and of traumatic experiences on entering motherhood in a foreign country. These mothers' representations of their children are affected by their ambivalence; the "child as a savior" and the "child as a persecutor" are in constant conflict within the mothers' psyche. The act of giving life is rooted in the mothers' histories and brings into question their very identities, their parentage and affiliations, as influenced by the hardships they have experienced. The arrival of a child is both a vulnerability factor as well as a source of tremendous resiliency. Therefore, it is essential to reflect on how to best welcome these mother-infant dyads in order to offer adapted and culturally sensitive care. Conclusion This paper offers a deeper review of a clinical reality often encountered in infant mental health with migrant and refugee populations. The perinatal period coinciding with migration is one of increased vulnerability and of potential revival of traumatic events. Giving birth in exile, especially when struggling with psychological trauma may impact maternal representations of their children. Children may then carry the burden of their histories or, inversely, become a source of creative potential for the mother-infant dyad. A transcultural approach is essential for a better understanding of the complex processes involved in becoming a mother in the context of trauma and/or migration and to improve care for mothers and their developing offspring.

[Countertransference with mother-baby dyads in a context of multiple traumas]. / Le contre-transfert avec les dyades mère-bébé dans un contexte de traumas multiples.

The encounter of mother-baby dyads in a context of a traumatic narrative renders the areas of transference and countertransference more complex, with multiple identification processes. What are the implications regarding the transmission of trauma to the child and how does it occur? The clinical case of a mother, with a past fraught with challenges and traumas, illustrates a way of accessing a child's experience of trauma via the clinician's countertransference.