The expression of histone 2A in onion (Allium cepa) during the onset of dormancy, storage and emergence from dormancy

• Published in: The New phytologist Vol. 143; no. 3; pp. 461 - 470
• Main Authors: CARTER, CAROL E., PARTIS, MICHAEL D., THOMAS, BRIAN
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.09.1999; Blackwell
• Subjects: Agronomy. Soil science and plant productions; Allium cepa; Biological and medical sciences; bulbing; bulbs; cell division; cultivars; Dormancy; dormancy breaking; Economic plant physiology; Fructification, ripening. Postharvest physiology; Fundamental and applied biological sciences. Psychology; gene expression; genetic variation; Growth and development; histone 2A; Histones; Horticulture; meristems; onion (Allium cepa); Onions; Plant bulbs; plant development; Plants; post‐harvest sprouting; RNA; Sprouting; Sprouts; storage; storage quality; Storage time; temporal variation; bulbing; onion (Allium cepa); post-harvest sprouting; histone 2A; dormancy; gene expression; Allium cepa; Monocotyledones; Histone H2A; Postharvest; Tissue specificity; Gene expression; Time variation; Meristem; Dormancy; Liliaceae; Storage; Vegetable crop; Dormancy breaking; Bulb; Angiospermae; Spermatophyta
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1046/j.1469-8137.1999.00484.x

The tissue-specific and developmental expression of histone 2A was studied in onion (Allium cepa ‘Robusta’), using northern blots. Histone 2A expression was enriched in basal tissues, particularly in the inner, meristematically active parts of bulbs. The expression was assessed during a time course of bulb development, dormancy onset and post-harvest sprouting in field-grown material. During bulb development histone 2A expression in the inner bulb declined rapidly during bulb ripening, reaching a minimum with the onset of dormancy. During post-harvest storage, expression increased slowly, reaching a peak in the spring, coinciding with the first observed sprout emergence. It was concluded that in onion, as in other plant systems, histone 2A expression is linked to cell division and dormancy level, the peak in expression during post-harvest storage indicating the time of dormancy breakage. In cultivars where post-harvest sprouting occurred much earlier or much later than in ‘Robusta’, this expression peak occurred at about the same time of year, regardless of sprouting time. It was concluded that differences in storage longevity between cultivars were not due to differing times of dormancy breakage. Factors controlling the rate of sprout emergence post-dormancy are likely to be major determinants of storage capacity.