Ananthakrishnan G, Xia Xiaodi, Amutha S, Singer Sima, Muruganantham M, Yablonsky Sara, Fischer Erwin, Gaba Victor
Department of Plant Pathology and Weed Science, ARO Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel.
Plant Cell Rep. 2007 Mar;26(3):267-76. doi: 10.1007/s00299-006-0235-1. Epub 2006 Oct 5.
Ultrasonic treatment (0.5-2 min) stimulated multiple shoot regeneration to high levels in vitro from recalcitrant cotyledon explants of commercial squash (Cucurbita pepo L.) cultivars Ma'yan and Bareqet, on Murashige and Skoog [Physiol Plant 15:473-497, 1962] (regeneration) medium augmented with 4.4 microM benzyladenine. At this stage, unsonicated control explants regenerated only a few very small shoots or bud-like structures. Ultrasound also stimulated massive explant growth. Ultrasound treatment resulted in further multiple shoot production (five times greater than control) after explant transfer to elongation medium (Murashige and Skoog [Physiol Plant 15:473-497, 1962] medium with 0.44 microM benzyladenine and 2.9 microM gibberellic acid). Longer ultrasonic treatments (5 or 10 min) promoted multiple shoot regeneration and explant growth accompanied by hyperhydration. Scanning electron microscope observations showed that 2 min ultrasound changed the joint area between epidermal cells and removed some of the surface from the cotyledon epidermal cells, without gross surface injury to the explants. Longer periods of ultrasound (5-10 min) caused further surface erosion. Rubbing the explant contact surface with chloroform or sandpaper emulated the effect of sonication on shoot regeneration and explant growth, demonstrating that ultrasound exerts its morphogenic influence by surface removal. Sonication of explants from other batches of squash seeds (of cultivars Ma'yan and True French), that regenerated without such treatment, reduced regeneration and caused hyperhydration. This is the first report of stimulation of in vitro regeneration by ultrasound treatment.
超声处理（0.5 - 2分钟）可刺激商业南瓜（西葫芦）品种“马彦”和“巴雷克特”难再生的子叶外植体在体外实现高水平的多芽再生，该外植体接种于添加了4.4微摩尔苄基腺嘌呤的Murashige和Skoog [《植物生理学》15:473 - 497, 1962]（再生）培养基上。在此阶段，未进行超声处理的对照外植体仅再生出少数非常小的芽或芽状结构。超声还刺激了外植体的大量生长。将外植体转移至伸长培养基（添加了0.44微摩尔苄基腺嘌呤和2.9微摩尔赤霉素的Murashige和Skoog [《植物生理学》15:473 - 497, 1962]培养基）后，超声处理导致进一步的多芽产生（比对照多五倍）。较长时间的超声处理（5或10分钟）促进了多芽再生和外植体生长，但伴有过度水合现象。扫描电子显微镜观察表明，2分钟的超声改变了表皮细胞之间的连接区域，并去除了子叶表皮细胞的部分表面，而对外植体没有明显的表面损伤。更长时间的超声处理（5 - 10分钟）导致进一步的表面侵蚀。用氯仿或砂纸摩擦外植体接触表面模拟了超声处理对芽再生和外植体生长的影响，表明超声通过表面去除发挥其形态发生影响。对其他批次南瓜种子（“马彦”和“真法国”品种）未经此类处理即可再生的外植体进行超声处理，降低了再生率并导致过度水合。这是关于超声处理刺激体外再生的首次报道。
