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Differential Reactivity in Epidermal Cells of Begonia rex Excised and Grown in vitro
Author(s) -
CHLYAH AVERIL,
VAN MARIE TRAN THANH
Publication year - 1975
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1975.tb03860.x
Subject(s) - explant culture , epidermis (zoology) , cytokinin , botany , biology , in vitro , meristem , auxin , microbiology and biotechnology , biochemistry , shoot , anatomy , gene
Thin explants composed of the epidermis and underlying collenchyma excised from leaf veins of Begonia rex and cultured in vitro are capable of neoformation of unicellular hairs, roots and buds. Unicellular hairs were formed over the entire surface of the explant when 10 −6 M indole acetic acid or 10 −7 M naphthaleneacetic acid (NAA) was added to the basal medium; each epidermal cell was potentially involved. The epidermis was most sensitive to a NAA treatment during the first few days of culture but 30% of the explants could still react after 4 days of culture without NAA. When NAA (5 × 10 −7 M ) and a cytokinin, zeatin (10 −7 M ), were added together, roots were formed from epidermal tissue after numerous divisions in the original cells. Their initiation was not related to particular cells. Buds were formed when a cytokinin (10 −6 M ) was added to the basal medium; bud meristems were formed from small groups of cells surrounding basal cells of glandular hairs. Hair formation was inhibited by either high (32–27°C) or low (12°C) temperatures applied continuously. 32–27°C seemed to inhibit elongation of the hairs specifically, whereas 12°C inhibited earlier phases in hair formation. This hypothesis was supported by short temperature treatments applied at different times during hair formation.