Plant Developmental Genetics, Hormone Signaling

Land plants' success to colonize different continental environments lies in part in their ability to produce seeds: structures encapsulating plant embryos, keeping them in an inert and osmotolerant state. The first step towards the adult phase of the plant is that of seed germination, a process whereby the embryo develops into a photosynthetic young seedling.

Since the embryo abandons a highly protected state, it is not surprising that germination is controlled by the environmental conditions faced by the seed. Thus, germination responds to the quality of light (e.g. favorable sun light vs unfavorable canopy light) or water (e.g. fresh vs salty water). Environmental cues determine the levels of the phytohormones gibberrellic acid (GA) and abscisic acid (ABA). GA is necessary to initiate germination by promoting the destruction of germination repressors; the DELLA factors RGL2, GAI and RGA. ABA is synthesized upon osmotic stress and blocks germination by inducing the expression of germination repressors; the transcription factors ABI3 and ABI5.

Our work mainly focuses on understanding how GA- and ABA-dependent control of seed germination is coordinated in response to environmental cues.

• ICE1 and ZOU determine the depth of primary seed dormancy in Arabidopsis independently of their role in endosperm development
  MacGregor, DR; Zhang, NC; Iwasaki, M; Chen, M; Dave, A; Lopez-Molina, L; Penfield, S
  PLANT JOURNAL, 98 (2):277-290; 10.1111/tpj.14211 APR 2019
• Non-canonical RNA-directed DNA methylation participates in maternal and environmental control of seed dormancy
  Iwasaki, M; Hyvarinen, L; Piskurewicz, U; Lopez-Molina, L
  ELIFE, 8 10.7554/eLife.37434 MAR 26 2019
• The plant pathogen Pseudomonas aeruginosa triggers a DELLA-dependent seed germination arrest in Arabidopsis
  Chahtane, H; Fuller, TN; Allard, PM; Marcourt, L; Queiroz, EF; Shanmugabalaji, V; Falquet, J; Wolfender, JL; Lopez-Molina, L
  ELIFE, 7 10.7554/eLife.37082 AUG 28 2018
• Chloroplast Biogenesis Controlled by DELLA-TOC159 Interaction in Early Plant Development
  Shanmugabalaji, V; Chahtane, H; Accossato, S; Rahire, M; Gouzerh, G; Lopez-Molina, L; Kessler, F
  CURRENT BIOLOGY, 28 (16):2616-+; 10.1016/j.cub.2018.06.006 AUG 20 2018
• The plant pathogen Pseudomonas aeruginosa triggers a DELLA-dependent seed germination arrest in Arabidopsis
  Chahtane, Hicham; Fuller, Thanise Nogueira; Allard, Pierre-Marie; et al.
  ELIFE   Volume: 7     Article Number: e37082   DOI: 10.7554/eLife.37082  Published: AUG 28 2018
• Chloroplast Biogenesis Controlled by DELLA-TOC159 Interaction in Early Plant Development
  Shanmugabalaji, Venkatasalam; Chahtane, Hicham; Accossato, Sonia; et al.
  CURRENT BIOLOGY   Volume: 28   Issue: 16   Pages: 2616-+ 10.1016/j.cub.2018.06.006  Published: AUG 20 2018
• A Maternally Deposited Endosperm Cuticle Contributes to the Physiological Defects of transparent testa Seeds
  Loubery, Sylvain; De Giorgi, Julien; Utz-Pugin, Anne; et al.
  PLANT PHYSIOLOGY   Volume: 177   Issue: 3   Pages: 1218-1233 10.1104/pp.18.00416  Published: JUL 2018
• Primary seed dormancy: a temporally multilayered riddle waiting to be unlocked 
  Chahtane, Hicham; Kim, Woohyun; Lopez-Molina, Luis 
  JOURNAL OF EXPERIMENTAL BOTANY, 68 (4): 857-869 10.1093/jxb/erw377  FEB 2017

• Hormone signaling (Abscisic Acid, Gibberellic Acid)
• Biosynthesis and action of the plant hormones Absicisic acid and Gibberellins
• Phytochromes, light responses
• Plant Developmental Genetics

• Chemical signaling in plants
• Embryogenesis, seed maturation
• Plant responses to environmental signals
• Auxin, ethylene and brassinosteroid signaling