Query (optional)   in Class  All Allele Author Colleague Collection Assembly Gene Gene Class Gene Product Germplasm Image Journal Keyword Library Locus Map Map Data Marker Pathology Polymorphism Probe Protein QTL Rearrangement Reference Sequence Species Trait Trait Study Two Point Data  

---

GrainGenes Reference Report: PLA-215-51

[Submit comment/correction]

Reference	PLA-215-51
Title	Induction of (1 -> 3,1 -> 4)-beta-D-glucan hydrolases in leaves of dark-incubated barley seedlings
Journal	Planta
Year	2002
Volume	215
Pages	51-59
Author	Roulin S Buchala AJ Fincher GB
Abstract	Summary: When seedlings of barley (Hordeum vulgare L.) were transferred from a natural light/dark cycle into darkness, (1 leads to 3,1 leads to 4)-beta-D-glucan endohydrolase (EC 3.2.1.73) activity in leaf extracts increased 3- to 4-fold after 2 days. Activity decreased to normal levels within a day if the light/dark cycle was restored. Although there are two (1 leads to 3, 1 leads to 4)-beta-D-glucan endohydrolase isoenzymes in barley, the increased enzyme activity in dark-grown seedlings was attributable entirely to increases in isoenzyme EI. Northern hybridization analyses confirmed that mRNA transcripts encoding (1 leads to 3, 1 leads to 4)-beta-D-glucan endohydrolase isoenzyme EI accumulated in the leaves of dark-incubated seedlings; no isoenzyme EII mRNA was detected. Activity of beta-D-glucan glucohydrolases also increased 10-fold after 2 days of dark treatment. The latter, broad-specificity enzymes release glucose from (1 leads to 3, 1 leads to 4)-beta-D-glucans and from beta-D-oligoglucosides released by (1 leads to 3, 1 leads to 4)-beta-D-glucan endohydrolases. Consistent with the activity patterns of these enzymes, the (1 leads to 3, 1 leads to 4)-beta-D-glucan content of leaf cell walls decreased by about 30% when barley seedlings were transferred into darkness. Soluble sugars in the leaves decreased by about 60% during the same period. Because no measurable leaf elongation was detected during the various light/dark treatments, the enzymes were unlikely to be participating in wall loosening and cell elongation. Instead, the results suggest that cell wall (1 leads to 3, 1 leads to 4)-beta-D-glucans can be re-mobilized in the non-elongating, dark-incubated leaves and the glucose so generated could serve as an energy source under conditions of sugar depletion
External Databases	Pubmed: 12012241
Keyword	[ Hide all but 1 of 42 ] (1 -> 3,1 -> 4)-beta-d-glucan (1 -> 3,1 -> 4)-beta-d-glucan endohydrolase barley barley seedlings beta-d-glucan beta-d-glucan glucohydrolase beta-glucanases cell cell elongation cell wall cis-elements cycle dark dark induction darkness depletion developmental regulation elongation endohydrolases energy gene expression glucose hordeum hybridization hydrolases increase induction leaf elongation leaf senescence messenger rna mrna northern northern hybridization primary-cell walls seedling soluble sugars source sugar sugar starvation sugars wall walls

GrainGenes is a product of the Agricultural Research Service of the US Department of Agriculture.