Gravitropism in tip-growing cells

被引:41
作者
Braun, M
机构
[1] Botanisches Institut,
[2] Rheinische Friedrich-Wilhelms-Universität Bonn,undefined
关键词
Chara; (rhizoids; protonemata); cytoskeleton; gravitropism; moss protonemata; statoliths; tip-growth;
D O I
10.1007/PL00008098
中图分类号
Q94 [植物学];
学科分类号
071001 ;
摘要
Unicellular tip-growing cells are excellent experimental systems in which to study gravitropism because cell extension, gravity sensing and the gravity response are all confined to the apical dome. Thus various approaches can be used to determine the distinct steps of the short gravitropic signal-transduction chain, which lacks a signal-transmission phase between the gravity-sensing cells and the competent responding target cells. Single-cell systems readily allow in-vivo observation of cellular processes during gravistimulation at I g, centrifugation, clinostatting and in microgravity, as well as permitting fluorescence labeling. Such diverse studies have revealed fascinating information on the mechanism of gravitropic tip growth, especially on the important role of the cytoskeleton in the positioning of the statoliths and in organizing and adjusting the Spitzenkorper. A hypothesis explaining the negative and positive gravitropism of Chara rhizoids and Chara protonemata has been put forward, which emphasizes the role of the actin cytoskeleton in the process of gravitropic tip-growth. Differences in the gravitropic responses of single-cell systems, however, reflect a diversity of gravitropic mechanisms, and represent an example of parallel evolution.
引用
收藏
页码:S11 / S19
页数:9
相关论文
共 54 条
[51]   AMYLOPLASTS AS POSSIBLE STATOLITHS IN GRAVITROPIC PROTONEMATA OF THE MOSS CERATODON-PURPUREUS [J].
WALKER, LM ;
SACK, FD .
PLANTA, 1990, 181 (01) :71-77
[52]   Ultrastructural analysis of cell component distribution in the apical cell of Ceratodon protonemata [J].
Walker, LM ;
Sack, FD .
PROTOPLASMA, 1995, 189 (3-4) :238-248
[53]   RECOVERY OF GRAVITROPISM AFTER BASIPETAL CENTRIFUGATION IN PROTONEMATA OF THE MOSS CERATODON-PURPUREUS [J].
WALKER, LM ;
SACK, FD .
CANADIAN JOURNAL OF BOTANY-REVUE CANADIENNE DE BOTANIQUE, 1991, 69 (08) :1737-1744
[54]   TIME-LAPSE ANALYSIS OF GRAVITROPISM IN CERATODON-PROTONEMATA [J].
YOUNG, JC ;
SACK, FD .
AMERICAN JOURNAL OF BOTANY, 1992, 79 (12) :1348-1358