Helena Carvalho

Helena Carvalho is a principal investigator of the university of Porto dedicated to the study of plant biology. She graduated in Biology at University of Porto and holds a PhD in plant molecular biology from Faculdade de Ciências, UP. Her research was mainly developed at the Instituto de Biologia Molecular e Celular, UP (IBMC), where she directed a research group dedicated to the study of nitrogen assimilation in plants. She is also an affiliated professor at Instituto de Ciências Biomédicas Abel Salazar (ICBAS), where she teaches plant molecular biology. She recently joined CIBIO-InBIO, integrating the group PLANTBIO. 

Main research interest is in understanding the molecular mechanisms that plants use to acquire and recycle nitrogen, with a special focus on symbiotic nitrogen fixation. She is addressing this question using the symbiotic model system Medicago truncatula- Sinorhizobium meliloti. Her work is primarily focused on the study of Glutamine Synthetase (GS), a crucial enzyme in nitrogen metabolism as it catalyzes the first step at which inorganic nitrogen is brought into cellular metabolism. The essential role performed by GS makes it a prime target for herbicidal compounds, but also a suitable intervention point for the improvement of crop yields. Major recent research breakthroughs include: the disclosure of the three-dimensional structure of the cytosolic and plastid-located enzymes; the discovery of novel nitric oxide–mediated regulatory controls operating at the post-translational level; the discovery of a seed specific plastid located GS related to seed protein storage synthesis, which is unique to M.truncatula and closely related species; and the discovery of a family of genes encoding GS of the prokaryotic type in M.truncatula, which are not catalytically active for glutamine synthesis but rather involved in nitrogen signaling. These studies generate basic knowledge necessary for the manipulation of nitrogen assimilation, towards the long-term goal of obtaining plants more efficient in terms of nitrogen utilization, better protein content and increased productivity. 

ORCID