Arabidopsis lox3 lox4 double mutants are male sterile
and defective in global proliferative arrest
Daniela Caldelari
•
Gaoge Wang
•
Edward E. Farmer
•
Xinnian Dong
Received: 15 June 2010 / Accepted: 30 September 2010 / Published online: 3 November 2010
Ó Springer Science+Business Media B.V. 2010
Abstract Fertility and flower development are both
controlled in part by jasmonates, fatty acid-derived medi-
ators produced via the activity of 13-lipoxygenases
(13-LOXs). The Arabidopsis thaliana Columbia-0 refer-
ence genome is predicted to encode four of these enzymes
and it is already known that one of these, LOX2, is dis-
pensable for fertility. In this study, the roles of the other
three 13-LOXs (LOX3, LOX4 and LOX6) were investi-
gated in single and double mutants. Four independent lox3
lox4 double mutants assembled with different mutated lox3
and lox4 alleles had fully penetrant floral phenotypes,
displaying abnormal anther maturation and defective
dehiscence. The plants were no longer self-fertile and
pollen was not viable. Fertility in the double mutant was
restored genetically by complementation with either the
LOX3 or the LOX4 cDNAs and biochemically with exog-
enous jasmonic acid. Furthermore, deficiency in LOX3 and
LOX4 causes developmental dysfunctions, compared to
wild type; lox3 lox4 double mutants are taller and develop
more inflorescence shoots and flowers. Further analysis
revealed that developmental arrest in the lox3 lox4 inflo-
rescence occurs with the production of an abnormal car-
pelloid flower. This distinguishes lox3 lox4 mutants from
the wild type where developmentally typical flower buds
are the terminal inflorescence structures observed in both
the laboratory and in nature. Our studies of lox3 lox4 as
well as other jasmonic acid biosynthesis and perception
mutants show that this plant hormone is not only required
for male fertility but also involved in global proliferative
arrest.
Keywords Lipoxygenase Á Jasmonate Á Male sterility Á
Carpelloid terminal flower
Abbreviations
LOX Lipoxygenase
AOS Allene oxide synthase
DAD1 Defective in anther dehiscence1
JA Jasmonic acid
LNA a-linolenic acid
CaMV 35S promoter Cauliflower mosaic virus promoter
WT Wild type
FA Fatty acid
GPA Global proliferative arrest
Introduction
Lipoxygenases (LOXs) are found in most eukaryote lin-
eages where they typically catalyze the oxygenation of
fatty acids (FAs) containing 1(Z), 4(Z) pentadienyl motifs
(Schneider et al. 2007). In plants oxygenation can occur on
Electronic supplementary material The online version of this
article (doi:10.1007/s11103-010-9701-9) contains supplementary
material, which is available to authorized users.
D. Caldelari Á G. Wang Á X. Dong
Department of Biology, Duke University, Durham,
North Carolina, USA
D. Caldelari (&) Á E. E. Farmer
Plant Molecular Biology, University of Lausanne,
Biophore, CH-1015, Lausanne, Switzerland
e-mail: daniela.caldelari@unil.ch
E. E. Farmer
e-mail: edward.farmer@unil.ch
Present Address:
G. Wang
College of Marine Life Sciences, Ocean University of China,
Qingdao, People’s Republic of China
123
Plant Mol Biol (2011) 75:25–33
DOI 10.1007/s11103-010-9701-9