Planta

, Volume 230, Issue 1, pp 119–134

The role of root apoplastic transport barriers in salt tolerance of rice (Oryza sativa L.)

  • Pannaga Krishnamurthy
  • Kosala Ranathunge
  • Rochus Franke
  • H. S. Prakash
  • Lukas Schreiber
  • M. K. Mathew
Original Article

DOI: 10.1007/s00425-009-0930-6

Cite this article as:
Krishnamurthy, P., Ranathunge, K., Franke, R. et al. Planta (2009) 230: 119. doi:10.1007/s00425-009-0930-6

Abstract

Increasing soil salinity reduces crop yields worldwide, with rice being particularly affected. We have examined the correlation between apoplastic barrier formation in roots, Na+ uptake into shoots and plant survival for three rice (Oryza sativa L.) cultivars of varying salt sensitivity: the salt-tolerant Pokkali, moderately tolerant Jaya and sensitive IR20. Rice plants grown hydroponically or in soil for 1 month were subjected to both severe and moderate salinity stress. Apoplastic barriers in roots were visualized using fluorescence microscopy and their chemical composition determined by gas chromatography and mass spectrometry. Na+ content was estimated by flame photometry. Suberization of apoplastic barriers in roots of Pokkali was the most extensive of the three cultivars, while Na+ accumulation in the shoots was the least. Saline stress induced the strengthening of these barriers in both sensitive and tolerant cultivars, with increase in mRNAs encoding suberin biosynthetic enzymes being detectable within 30 min of stress. Enhanced barriers were detected after several days of moderate stress. Overall, more extensive apoplastic barriers in roots correlated with reduced Na+ uptake and enhanced survival when challenged with high salinity.

Keywords

Apoplastic barriersCasparian bandsEndodermisExodermisRiceSalt tolerance

Abbreviations

FW

Fresh weight

DW

Dry weight

OPR

Outer part of the root

CB

Casparian band

SL

Suberin lamellae

Supplementary material

425_2009_930_MOESM1_ESM.pdf (78 kb)
Supplementary Figure 1 (PDF 78 kb)
425_2009_930_MOESM2_ESM.pdf (184 kb)
Supplementary Figure 2 (PDF 185 kb)

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • Pannaga Krishnamurthy
    • 1
    • 3
  • Kosala Ranathunge
    • 2
  • Rochus Franke
    • 2
  • H. S. Prakash
    • 3
  • Lukas Schreiber
    • 2
  • M. K. Mathew
    • 1
  1. 1.National Centre for Biological Sciences, TIFRBangaloreIndia
  2. 2.Institute of Cellular and Molecular Botany (IZMB)University of BonnBonnGermany
  3. 3.Department of Studies in Applied Botany and BiotechnologyUniversity of MysoreMysoreIndia