In-vivo measurement of cell-wall extensibility in maize coleoptiles: Effects of auxin and abscisic acid

✍ Scribed by U. Kutschera; P. Schopfer

• Publisher: Springer-Verlag
• Year: 1986
• Tongue: English
• Weight: 470 KB
• Volume: 169
• Category: Article
• ISSN: 0032-0935
• DOI: 10.1007/bf00392142

✦ Synopsis

Plastic and elastic in-vivo extensibilities (gpl and Eel, respectively) of cell walls of growing maize (Zea mays L.) coleoptile segments were measured by stretching living tissue at constant force (creep test) in an extensiometer. The linear displacement transducer used as a measuring device permits the determination of load-induced extensions in the range of 0-1% of the segment's length, leading to a minimal disturbance of the hydraulic parameters of the tissue and allowing the measurement of unidirectional cell-wall creep at virtually unchanged turgot and metabolic activity. A reinvestigation of the time-course of indole-3=acetic acid-promoted and abscisic acid-inhibited wall loosening revealed that the in-vivo creep test yields results very similar to those obtained previously with the in-vitro creep test [Kutschera and Schopfer, 1986, Planta 167, 527-535]. The hormones affect elongation rate and Ep~ in a closely correlated manner both in step-up as well as stepdown growth changes whereas Ee~ remains unaltered. It is argued that both hormones influence growth by modifying Epl of the outer epidermis and that this effect can be quantitatively measured, in relative units, by either the in-vivo or the in-vitro creep test.