Ross J. J., Murfet I. C., Reid J. B.
Department of Plant Science, University of Tasmania, GPO Box 252C, Hobart, Tasmania 7001, Australia.
Plant Physiol. 1993 Jun;102(2):603-608. doi: 10.1104/pp.102.2.603.
In sweet pea (Lathyrus odoratus L.) the mutant allele l reduced the level of gibberellin A1 (GA1) in expanding leaflets and resulted in smaller, more oval leaflets compared with the wild type. The apical portions of 6-d-old wild-type (L) seedlings also contained less GA1 and produced smaller, more oval leaflets than did comparable 20-d-old L seedlings. Application of GA1 markedly altered leaflet shape and, at certain dosages, restored the wild-type shape and size to leaflets of the l (dwarf) mutant. Taken together, these observations indicate that GA1 performs a regulatory role in the control of leaf growth in this species. The levels of GA1 precursors in the wild type were also determined. Rapidly expanding internodes contained much more gibberellin A19 (GA19) than gibberellin A20 (GA20), whereas the opposite was true for expanding leaflets. Although in entire apical portions of established seedlings the level of GA20 exceeded that of GA19, apical portions of very young seedlings contained more GA19 than GA20. Basal stem tissue of established seedlings also contained substantially more GA19 than GA20 or GA1. Both stems and leaflets from the basal portion of the plant contained much less GA20 and GA1 than did the rapidly expanding apical tissue. The implications of these results for the regulation of GA1 biosynthesis are discussed.
在香豌豆（Lathyrus odoratus L.）中，突变等位基因l降低了正在展开的小叶中赤霉素A1（GA1）的水平，与野生型相比，导致小叶更小且更呈椭圆形。6日龄野生型（L）幼苗的顶端部分也含有较少的GA1，并且与20日龄的L幼苗相比，产生的小叶更小且更呈椭圆形。施用GA1显著改变了小叶形状，并且在某些剂量下，使l（矮化）突变体的小叶恢复到野生型的形状和大小。综合这些观察结果表明，GA1在该物种叶片生长的控制中发挥调节作用。还测定了野生型中GA1前体的水平。快速伸长的节间中含有的赤霉素A19（GA19）比赤霉素A20（GA20）多得多，而正在展开的小叶情况则相反。尽管在已长成的幼苗整个顶端部分中GA20的水平超过GA19，但非常幼嫩幼苗的顶端部分中GA19比GA20多。已长成幼苗的基部茎组织中GA19的含量也大大高于GA20或GA1。植物基部的茎和小叶中GA20和GA1的含量比快速伸长的顶端组织中的含量少得多。讨论了这些结果对GA1生物合成调控的意义。
