Endogenous phytohormones of frankincense producing Boswellia sacra tree populations

PLoS One. 2018 Dec 19;13(12):e0207910. doi: 10.1371/journal.pone.0207910. eCollection 2018.


Boswellia sacra, an endemic tree to Oman, is exposed to man-made incisions for commercial level frankincense production, whereas unsustainable harvesting may lead to population decline. In this case, assessment of endogenous phytohormones (gibberellic acid (GA), indole-acetic acid (IAA), salicylic acid (SA) and kinetin) can help to understand population health and growth dynamics. Hence, it was aimed to devise a robust method using Near-Infrared spectroscopy (NIRS) coupled with multivariate methods for phytohormone analysis of thirteen different populations of B. sacra. NIRS data was recorded in absorption mode (10000-4000 cm-1) to build partial least squares regression model (calibration set 70%). Model was externally cross validated (30%) as a test set to check their prediction ability before the application to quantify the unknown amount of phytohormones in thirteen different populations of B. sacra. The results showed that phytohormonal contents varied significantly, showing a trend of SA>GA/IAA>kinetin across different populations. SA and GA contents were significantly higher in Pop13 (Hasik), followed by Pop2 (Dowkah)-an extreme end of B. sacra tree cover in Dhofar region. A similar trend in the concentration of phytohormones was found when the samples from 13 populations were subjected to advance liquid chromatography mass spectrophotometer and gas chromatograph with selected ion monitor analysis. The current analysis provides alternative tool to assess plant health, which could be important to in situ propagation of tree population as well as monitoring tree population growth dynamics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Boswellia / growth & development
  • Boswellia / metabolism*
  • Chromatography, Gas
  • Chromatography, Liquid
  • Frankincense / metabolism*
  • Gibberellins / metabolism
  • Indoleacetic Acids / metabolism
  • Kinetin / metabolism
  • Least-Squares Analysis
  • Mass Spectrometry
  • Oman
  • Plant Growth Regulators / analysis
  • Plant Growth Regulators / metabolism*
  • Regression Analysis
  • Salicylic Acid / metabolism
  • Spectroscopy, Near-Infrared
  • Trees / growth & development
  • Trees / metabolism


  • Gibberellins
  • Indoleacetic Acids
  • Plant Growth Regulators
  • indoleacetic acid
  • gibberellic acid
  • Salicylic Acid
  • Kinetin
  • Frankincense

Grants and funding

This study was supported by The Research Council Oman under their Open Research Grant (ORG/BSER/15/007). All the funding or sources of support received during this specific study (whether external or internal to your organization) had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.