Chin J Plant Ecol ›› 2019, Vol. 43 ›› Issue (2): 139-151.DOI: 10.17521/cjpe.2018.0201

• Research Articles • Previous Articles     Next Articles

Correlation between endogenous hormone and the adaptability of Chinese fir with high phosphorus-use efficiency to low phosphorus stress

ZOU Xian-Hua1,2,HU Ya-Nan1,WEI Dan1,CHEN Si-Tong1,WU Peng-Fei1,2,MA Xiang-Qing1,2,*()   

  1. 1 Forestry College, Fujian Agriculture and Forestry University, Fuzhou 350002, China
    2 Chinese Fir Engineering Technology Research Center of State Forestry Administration, Fuzhou 350002, China
  • Received:2018-08-16 Accepted:2018-12-04 Online:2019-02-20 Published:2019-06-04
  • Contact: MA Xiang-Qing
  • Supported by:
    Supported by the National Natural Science Foundation of China(31600502);Supported by the National Natural Science Foundation of China(U1405211)

Abstract: <i>Aims</i>

Hormones are important signals for plants adaption to environmental stresses. To understand the mechanism of plants adaptation to nutrient deficiency from the perspective of hormone regulation is of great significance for breeding the genotypes with high phosphorus (P)-use efficiency.

<i>Methods</i>

This study investigated the correlation between hormone content and the adaptability of Chinese fir (Cunninghamia lanceolata) to low P stress by examining the changes of hormone content, root morphology, root dry matter and root P distribution patterns in the passive tolerance (M1) and active activation (M4) genotypes under low P stress at different treatment periods.

<i>Important findings</i>

No correlation was found between the foliar hormone contents and the adaptive characteristics of M1 and M4 under low P stress, although the root hormone content was significantly correlated with the growth index of roots. Low P stresses increased root IAA contents in M1 and M4 after 27 h of treatments and increased continuously with the prolongation of time. The IAA contents were positively correlated with surface area, volume and length of roots in both M1 and M4 (p < 0.05), suggesting that the increase of IAA induced root growth in both genotypes. Specifically, we observed an obvious phenomenon of IAA transportation from leaves to roots in M4, along with stronger root growth of M4 compared with that of M1. Meanwhile, low P stress increased the root-shoot ratio of M4, suggesting that root growth prompted more dry matter distribution to roots. Similarly, the ABA and GA3 contents in both M1 and M4 roots also increased as P availability decreased, but they showed a trend toward decrease over time and a negative correlation with root growth. The ZT contents in the root lower under low P treatment, yet there was no significant correlation between its contents and the low P adaptive characteristics of M1 and M4. Our results indicated that the contents of root IAA, ABA, and GA3 in Chinese fir clones with high P-use efficiency were closely related to the morphological changes of the roots. These comprehensive regulations of different organs is an essential survival strategy for plants to adapt to low P stress.

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Key words: low phosphorus stress, endogenous hormone, high phosphorus-use efficiency, Chinese fir, root morphology, root shoot ratio, nutrient distribution