Hanson J, Johannesson H, Engström P
Department of' Physiological Botany, Evolutionary Biology Center, Uppsala University, Sweden.
Plant Mol Biol. 2001 Feb;45(3):247-62. doi: 10.1023/a:1006464907710.
ATHB13 is a new member of the homeodomain leucine zipper (HDZip) transcription factor family of Arabidopsis thaliana. Constitutive high-level expression of the ATHB13 cDNA in transgenic plants results in altered development of cotyledons and leaves, specifically in plants grown on media containing metabolizable sugars. Cotyledons and leaves of sugar-grown transgenic plants are more narrow and the junction between the petiole and the leaf blade less distinct, as compared to the wild type. High-level expression of ATHB13 affects cotyledon shape by inhibiting lateral expansion of epidermal cells in sugar-treated seedlings. Experiments with non-metabolizable sugars indicate that the alteration in leaf shape in the ATHB13 transgenics is mediated by sucrose sensing. ATHB13 further affects a subset of the gene expression responses of the wild-type plant to sugars. The expression of genes encoding beta-amylase and vegetative storage protein is induced to higher levels in response to sucrose in the transgenic plants as compared to the wild type. The expression of other sugar-regulated genes examined is unaffected by ATHB13. These data suggest that ATHB13 may be a component of the sucrose-signalling pathway, active close to the targets of the signal transduction.
ATHB13是拟南芥同源异型域亮氨酸拉链（HDZip）转录因子家族的一个新成员。在转基因植物中组成型高水平表达ATHB13 cDNA会导致子叶和叶片发育改变，特别是在含有可代谢糖的培养基上生长的植物中。与野生型相比，在含糖类培养基上生长的转基因植物的子叶和叶片更窄，叶柄与叶片之间的连接处也不那么明显。ATHB13的高水平表达通过抑制经糖处理的幼苗中表皮细胞的横向扩展来影响子叶形状。使用不可代谢糖的实验表明，ATHB13转基因植物中叶片形状的改变是由蔗糖感知介导的。ATHB13进一步影响野生型植物对糖类的一部分基因表达反应。与野生型相比，转基因植物中编码β-淀粉酶和营养贮藏蛋白的基因在蔗糖响应下被诱导到更高水平。所检测的其他糖调节基因的表达不受ATHB13影响。这些数据表明，ATHB13可能是蔗糖信号通路的一个组成部分，在信号转导靶点附近起作用。
