Overexpression of a petunia zinc-finger gene alters cytokinin metabolism and plant forms.
Shoot branching and plant height are among the key factors that define the overall architecture of plants. We found that overexpression of a cDNA for a zinc-finger protein of petunia, designated Lateral shoot-Inducing Factor (LIF), in transgenic petunia plants resulted in a dramatic increase in lateral shoots and reduced plant height. LIF overexpression also caused a decrease in the number of cells in the stem, leaf, and flower, accompanied by enlargement of cells. trans-Zeatin was decreased while N6-(Delta2-isopentenyl)adenine was increased in the leaves of LIF-overexpressed petunia. Most of the riboside, ribotide, and glucoside forms were also increased. Expression analysis using a LIF::GUS fusion gene and RT-PCR suggested that LIF is specifically expressed around the bases of axillary buds and weakly in basal part of flowers in wild-type petunia. GFP-LIF-GUS fusion proteins were translocated into the nucleus when transiently expressed in onion epidermal cells. LIF overexpression resulted in enhanced branching also in tobacco and Arabidopsis, indicating the conservation of the response to LIF overexpression among dicotyledonous plants. On the basis of these results we discuss about possible functions of LIF.
Nakagawa
Hitoshi
H
Developmental Biology Laboratory, Plant Physiology Department, National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan.
Jiang
Chang-Jie
CJ
Sakakibara
Hitoshi
H
Kojima
Mikiko
M
Honda
Ichiro
I
Ajisaka
Hidetoshi
H
Nishijima
Takaaki
T
Koshioka
Masaji
M
Homma
Tamaki
T
Mander
Lewis N
LN
Takatsuji
Hiroshi
H
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics; D001483:Base Sequence; D003583:Cytokinins / Q000378:metabolism*; D035264:Flowers / Q000254:growth & development; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D032306:Petunia / Q000235:genetics* / Q000254:growth & development / Q000502:physiology*; D010641:Phenotype; D018515:Plant Leaves / Q000254:growth & development; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D018520:Plant Shoots / Q000254:growth & development; D030821:Plants, Genetically Modified; D014026:Nicotiana / Q000235:genetics; D016335:Zinc Fingers / Q000235:genetics / Q000502:physiology*
D003583:Cytokinins; D010940:Plant Proteins