Microspore embryogenesis and programmed cell death in barley: effects of copper on albinism in recalcitrant cultivars.
Albinism remains a major problem in cereal improvement programs that rely on doubled haploid (DH) technology, and the factors controlling the phenomenon are not well understood. Here we report on the positive influence of copper on the production of DH plants obtained through microspore embryogenesis (ME) in recalcitrant cultivars of barley (Hordeum vulgare L.). The presence of copper sulphate in the anther pre-treatment medium improved green DH plant regeneration from cultivars known to produce exclusively albino plants using classical procedures. In plastids, the effect of copper was characterized by a decrease in starch and a parallel increase in internal membranes. The addition of copper sulphate in the ME pre-treatment medium should enable breeders to exploit the genetic diversity of recalcitrant cultivars through DH technology. We examined programmed cell death (PCD) during microspore development to determine whether PCD may interfere with the induction of ME and/or the occurrence of albinism. By examining the fate of nuclei in various anther cell layers, we demonstrated that the kinetics of PCD in anthers differed between the barley cultivars Igri and Cork that show a low and a high rate of albinism, respectively. However, no direct correlation between PCD in the anther cell layers and the rate of albinism was observed and copper had no influence on the PCD kinetic in these cultivars. It was concluded that albinism following ME was not due to PCD in anthers, but rather to another unknown phenomenon that appears to specifically affect plastids during microspore/pollen development.
Jacquard
Cédric
C
Stress Défenses et Reproduction des Plantes, UFR Sciences Exactes et Naturelles, URVVCSE EA 2069, Université de Reims Champagne Ardenne, Bâtiment 18, BP 1039, 51687, Reims Cedex 2, France. cedric.jacquard@univ-reims.fr
Nolin
Frédérique
F
Hécart
Carine
C
Grauda
Dace
D
Rashal
Isaak
I
Dhondt-Cordelier
Sandrine
S
Sangwan
Rajbir S
RS
Devaux
Pierre
P
Mazeyrat-Gourbeyre
Florence
F
Clément
Christophe
C
D017209:Apoptosis; D018929:Cell Culture Techniques; D019327:Copper Sulfate / Q000494:pharmacology*; D003470:Culture Media / Q000494:pharmacology; D018744:DNA, Plant / Q000187:drug effects; D047108:Embryonic Development; D006238:Haploidy; D001467:Hordeum / Q000187:drug effects* / Q000196:embryology*; D010858:Pigmentation / Q000187:drug effects*; D018087:Plastids / Q000187:drug effects / Q000648:ultrastructure; D012038:Regeneration
D003470:Culture Media; D018744:DNA, Plant; D019327:Copper Sulfate