Ascorbate peroxidase (APX) enzyme is an integral
part of the plant tolerance response to
environmental stresses. As a first step towards the
study of the physiological role and the regulation
of the members of the Apx gene family, the orthologs
of the stress-sensitive cultivated tomato Solanum
lycopersicum cv. M82 (Lem) and of the wild salt-
tolerant species S. pennellii acc. Atico (Lpa) were
identified by utilizing the tomato EST database, and
characterized. The complete tomato Apx gene family
is comprised of genes encoding three cytosolic, two
peroxisomal, and two chloroplastic APXs. These genes
attained differential regulatory patterns in various
Lem and Lpa organs. More detailed study of Apx1 and
Apx2 genes, that are the products of a recent gene
duplication event, shows that they have already
attained differential regulation within and between
Lem and Lpa under control and stress conditions. It
is also suggested that due to lineage-specific gene
duplication and lose events, intricate phylogenetic
relationships exist among the members of the Apx
gene families.
part of the plant tolerance response to
environmental stresses. As a first step towards the
study of the physiological role and the regulation
of the members of the Apx gene family, the orthologs
of the stress-sensitive cultivated tomato Solanum
lycopersicum cv. M82 (Lem) and of the wild salt-
tolerant species S. pennellii acc. Atico (Lpa) were
identified by utilizing the tomato EST database, and
characterized. The complete tomato Apx gene family
is comprised of genes encoding three cytosolic, two
peroxisomal, and two chloroplastic APXs. These genes
attained differential regulatory patterns in various
Lem and Lpa organs. More detailed study of Apx1 and
Apx2 genes, that are the products of a recent gene
duplication event, shows that they have already
attained differential regulation within and between
Lem and Lpa under control and stress conditions. It
is also suggested that due to lineage-specific gene
duplication and lose events, intricate phylogenetic
relationships exist among the members of the Apx
gene families.