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Ultrastructure of stomatal development in Arabidopsis (Brassicaceae) leaves
Author(s) -
Zhao Liming,
Sack Fred D.
Publication year - 1999
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.2307/2656609
Subject(s) - guard cell , arabidopsis , biology , ultrastructure , botany , microtubule , microbiology and biotechnology , cell division , vacuole , meristem , cell wall , mutant , cytoplasm , cell , gene , genetics , shoot
Stomatal development was studied in wild‐type Arabidopsis leaves using light and electron microscopy. Development involves three successive types of stomatal precursor cells: meristemoid mother cells, meristemoids, and guard mother cells (GMCs). The first two types divide asymmetrically, whereas GMCs divide symmetrically. Analysis of cell wall patterns indicates that meristemoids can divide asymmetrically a variable number of times. Before meristemoid division, the nucleus and a preprophase band of microtubules become located on one side of the cell, and the vacuole on the other. Meristemoids are often triangular in shape and have evenly thickened walls. GMCs can be detected by their roughly oval shape, increased starch accumulation, and wall thickenings on opposite ends of the cells. Because these features are also found in developing stomata, stomatal differentiation begins in GMCs. The wall thickenings mark the division site in the GMC since they overlie a preprophase band of microtubules and occur where the cell plate fuses with the parent cell wall. Stomatal differentiation in Arabidopsis resembles that of other genera with kidney‐shaped guard cells. This identification of stages in stomatal development in wild‐type Arabidopsis provides a foundation for the analysis of relevant genes and of mutants defective in stomatal patterning, cell specification, and differentiation.