TITLE:
Seed Germination in Tomato: A Focus on Interaction between Phytochromes and Gibberellins or Abscisic Acid
AUTHORS:
Marina Alves Gavassi, Gabriela Cabral Fernandes, Carolina Cristina Monteiro, Lázaro Eustáquio Pereira Peres, Rogério Falleiros Carvalho
KEYWORDS:
Abscisic Acid, Gibberellins, Phytochromes, Seed Germination, Tomato
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.5 No.14,
July
3,
2014
ABSTRACT: Separately, it is well-documented that phytochromes (phys), gibberellin (GA) and abscisic acid (ABA) strongly control the seed germination in tomato. However, we hipothesized that phys interact with GA or ABA during this response. Thus, we make an analysis of seed germination of ABA deficient (sit), GA constitutive response (pro), phytochrome deficient (au) mutants as well as, specially, au sit and au pro double mutants of tomatoincubated in the dark or light conditions during 120 h [12 h intervals (i)]. Compared to au, which severelyreduced percentage germination (Gi%) and pro, which did not alter Gi%, au pro showed in the light enhanced Gi% and germination speed index (GSI) besides the reduced average germination time (AGT). Moreover, in the dark, germination of au pro was similar to pro. These results indicate that the mechanisms by which GA modulate germination in tomato are light dependent through the phy signaling, whereas intermediary values of Gi%, GSI and AGT in dark and light of au sit compared to au and sit single mutants indicate an additive effect of the au and sit mutations, suggesting that ABA and phy may act through the parallel signaling pathway.