Vegetative propagation through somatic embryogenesis in combination with the cryopreservation
of embryogenic lines is a major tool in conifer biotechnology. An important process during the
maturation phase of embryogenesis is the biosynthesis and deposition of storage proteins. The
accumulation of some abundant storage proteins in maturing cotyledonary somatic embryos (SE)
is much lower than in mature zygotic embryos (ZE) showing an important influence of storage
compounds on the quality of SE. Arginine constitutes a large portion of the amino acid pool in
storage proteins of conifers and therefore arginine biosynthesis and utiization is a relevant
metabolic pathway during pine embryogenesis and early growth.
Research in our laboratory is focused on maritime pine (Pinus pinaster Ait.), a broadly planted
conifer species in France, Spain and Portugal where it is distributed over approximately 4 million
hectares. This conifer species is also one of the most advanced model trees for genetic and
phenotypic studies and a large number of molecular and transcriptomic resources are currently
available.
With the aim to understand the molecular basis of the differential accumulation of storage proteins
in SE and ZE, the arginine metabolic pathway has been studied in maritime pine, in collaboration
with the French private institute FCBA. A general overview of this research programme will be
presented and discussed. The knowledge acquired from our studies will help to refine
biotechnological procedures for clonal propagation of conifers via somatic embryogenesis.
Funding support by:The Spanish Ministerio de Economía y Competitividad (BIO2015-69285-R)
and Junta de Andalucía (BIO-474). And the French Ministry of Agriculture (DGAL, N°2014-352,
QuaSeGraine project). The project also benefited from the technical support of the
XYLOBIOTECH facility (ANR-10-EQPX-16 XYLOFOREST).