Zhang L., Cohn N. S., Mitchell J. P.
Department of Environmental and Plant Biology and Molecular and Cellular Biology Program, Ohio University, Athens, Ohio 45701.
Plant Physiol. 1996 Nov;112(3):1111-1117. doi: 10.1104/pp.112.3.1111.
A full-length cell-wall invertase cDNA obtained from pea (Pisum sativum L.) seedlings was cloned previously. The gene exhibits tissue-specific expression, and both its transcript and enzyme activities are abundant only in root tissues. Mechanical wounding dramatically induced the accumulation of the cell-wall invertase mRNA in detached or intact leaves, stems, and roots. In both detached and intact tissues mRNA started to accumulate 3 h after wounding and in detached tissues (except root tissues) was much stronger and lasted longer compared with that in intact pea plants. The induction of cell-wall invertase by wounding was not systemic, since no significant increase of transcript was found in the unwounded tissues remote from the site of wounding. Accumulation of this cell-wall invertase was induced by abscisic or jasmonic acid, and in situ hybridization studies show that this invertase mRNA is differentially localized in wounded plant tissue, being most abundant in the phloem. mRNA accumulation was limited mainly to the wounded area; no significant increase was detected in the unwounded portions of the wounded stem segments. The results suggest that, as part of the wounding response, this cell-wall invertase may provide energy through hexose availability to companion cells in the phloem.
先前从豌豆（Pisum sativum L.）幼苗中获得了一个全长的细胞壁转化酶cDNA，并进行了克隆。该基因表现出组织特异性表达，其转录本和酶活性仅在根组织中丰富。机械损伤显著诱导了离体或完整叶片、茎和根中细胞壁转化酶mRNA的积累。在离体和完整组织中，mRNA在受伤后3小时开始积累，并且在离体组织（根组织除外）中比在完整豌豆植株中更强且持续时间更长。伤口对细胞壁转化酶的诱导不是系统性的，因为在远离伤口部位的未受伤组织中未发现转录本有显著增加。脱落酸或茉莉酸可诱导这种细胞壁转化酶的积累，原位杂交研究表明，这种转化酶mRNA在受伤植物组织中的定位不同，在韧皮部中最为丰富。mRNA积累主要局限于受伤区域；在受伤茎段的未受伤部分未检测到显著增加。结果表明，作为伤口反应的一部分，这种细胞壁转化酶可能通过向韧皮部中的伴胞提供己糖来提供能量。
