Chin J Plan Ecolo ›› 2004, Vol. 28 ›› Issue (2): 198-203.DOI: 10.17521/cjpe.2004.0029

• Research Articles • Previous Articles     Next Articles

CHANGES IN THE ENDOGENOUS PHYTOHORMONE CONTENT OF THE SUPER-XEROPHYTIC SHRUBLET, POTANINIA MONGOLICA, DURING FISSURATE GROWTH

HOU Yan-Wei, WANG Ying-Chun, YANG Chi   

  • Published:2004-02-10
  • Contact: HOU Yan-Wei

Abstract:

Potaninia mongolica is an archaic, single-species genus plant and is a member of the Rosaceae family. It is well adapted to drought environments. P. mongolica reproduces primarily by vegetative means, but it also can reproduce sexually. This species has two modes of vegetative reproduction: one is that the branches drop and grow new vegetal body and the other is by fissurate growth. Many other xerophilous plants in the Inner Mongolia West Erdos region share the same characteristic of fissurate growth, which is an adaptive strategy to drought environments. Correlated studies of fissurate growth are few, and this is the first report on the changes of the endogenous phytohormone content during fissurate growth.We determined the content of ABA, IAA, GA3, ZR in tissues of P. mongolica in different states of fissurate growth using ELISA (Enzyme-Linked Immunosorbent Assay), to relate changes of phytohormone content to changes during fissurate growth.The results are as follows: 1) in the four states measured, ABA content was the lowest in the leaf and the fissurate part during the fissurated state and highest in the root. Compared with other endogenous phytohormones, ABA content was the highest. 2) before fissuration, IAA accumulated greatly in the fissurate part, especially during the transitional state, and IAA content was the highest in the fissurate part. 3) during fissurate growth, changes in GA3 content followed that of the IAA content. 4) ZR content was also the highest in the fissurate part before fissuration. During fissurate growth, ZR content carried from the root to the fissurate part and the leaf decreased gradually, and, during the transitional state, the percent of ZR carried from the root to the fissurate part was higher; these were 19.44% and 20%. 5) IAA, GA3, and ZR mutually regulated and promoted the growth and splitting of the cells in the fissurate part, and the accumulation of ABA in P. mongolica roots was an adaptive response to its droughty environment.