Purification of β1,4 glucanase from ethylene‐treated leaflet abscission zones of Sambucus nigra

Abstract

Leaflet abscission in Sambucus nigra is the result of cell wall breakdown at the site of separation. Associated with wall degradation is an increase in the activity of the enzyme pl,4 giucanase (E.C.3-1.2-4) in the cells that comprise the abscission zone. The enzyme has been extracted from abscission zone tissue and purified using a substrate affinity column. A qualitative enzyme assay procedure has been developed and this has facilitated the purification process. The (31,4 giucanase enzyme has a pH optimum of 7 and a molecular mass of 54kDa. Antibodies have been raised to the purified protein. The role of the enzyme in the abscission process is discussed.

Identification and characterization of a proline-rich mRNA that accumulates during pod development in oilseed rape (Brassica napus L.)

“…Cellulase activity increases in the dehiscence zone from 35 DAA (data not shown) and precedes the first visible signs of cell wall breakdown by 15-20 days [24]. Therefore m R N A extracted from different developmental stages of pod development (40,45 and 50 DAA) were pooled in order to increase the chances of obtaining mRNAs that are preset prior to, and during, the process of dehiscence.…”

“…The process occurs at precise sites and involves coordinated cell wall breakdowns. Associated with cell separation is an increase in the activity of several hydrolytic enzymes including fl-l,4-glucanase (cellulase, EC 3.1.2.4) [40] and polygalacturonase (PG, EC 3.2.1.15) [37,38].…”

Characterisation of an mRNA encoding a metallothionein-like protein that accumulates during ethylene-promoted abscission of Sambucus nigra L. leaflets

“…The phenomenon is the consequence of a series of precisely co-ordinated events which lead to the loss of cell-to-cell cohesion. Cell wall breakdown has been proposed to be caused by the action of several hydrolytic enzymes and this has been well documented at both a biochemical Webb et al 1993) and molecular level (Tucker et al 1988;Taylor et al 1994). There is convincing evidence that the progress of this co-ordinated cell separation can be regulated by ethylene and it has been proposed that the timing of abscission is strongly influenced in vivo by ethylene produced by tissue distal to the site of abscission (Sexton and Roberts 1982).…”

Temporal and spatial expression of mRNAs encoding pathogenesis‐related proteins during ethylene‐promoted leaflet abscission in Sambucus nigra*

“…Abscission of the leallets of the herbaceous plant Sanihtictis nigra has proved to be an effective model system for the study of abscission, as the zone of sepatation is made up of a sufficient number of rows of cells to facilitate the extraction of proteins and nucleic acids. S(udies on this plant have revealed that during ethylene-stitnulated leaflet abscission (he activities of both polygalacturonase and /3-1,4-glucanase increase specifically at the site of separation Webb et al 1993) and that this is correlated with an inctease in the expression of genes encoding these etizytnes (Taylor et al 1994;Roberts et al 1997). Additional ptoteins have been teported to be produced dut--ing leaf abscission in other species (Kelly et al 1987;Gomez Lim et al 1987).…”