Difference in root K+ retention ability and reduced sensitivity of K+-permeable channels to reactive oxygen species confer differential salt tolerance in three Brassica species.
J Exp Bot. 2016 08; 67(15):4611-25.JE

Abstract

Brassica species are known to possess significant inter and intraspecies variability in salinity stress tolerance, but the cell-specific mechanisms conferring this difference remain elusive. In this work, the role and relative contribution of several key plasma membrane transporters to salinity stress tolerance were evaluated in three Brassica species (B. napus, B. juncea, and B. oleracea) using a range of electrophysiological assays. Initial root growth assay and viability staining revealed that B. napus was most tolerant amongst the three species, followed by B. juncea and B. oleracea At the mechanistic level, this difference was conferred by at least three complementary physiological mechanisms: (i) higher Na(+) extrusion ability from roots resulting from increased expression and activity of plasma membrane SOS1-like Na(+)/H(+) exchangers; (ii) better root K(+) retention ability resulting from stress-inducible activation of H(+)-ATPase and ability to maintain more negative membrane potential under saline conditions; and (iii) reduced sensitivity of B. napus root K(+)-permeable channels to reactive oxygen species (ROS). The last two mechanisms played the dominant role and conferred most of the differential salt sensitivity between species. Brassica napus plants were also more efficient in preventing the stress-induced increase in GORK transcript levels and up-regulation of expression of AKT1, HAK5, and HKT1 transporter genes. Taken together, our data provide the mechanistic explanation for differential salt stress sensitivity amongst these species and shed light on transcriptional and post-translational regulation of key ion transport systems involved in the maintenance of the root plasma membrane potential and cytosolic K/Na ratio as a key attribute for salt tolerance in Brassica species.

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Authors+Show Affiliations

Chakraborty K

Department of Plant Physiology, ICAR-Directorate of Groundnut Research, Junagadh, Gujarat-362 001, India School of Land and Food and Tasmanian Institute for Agriculture, University of Tasmania, Hobart, Private Bag 94, Tas 7001, Australia.

Bose J

School of Land and Food and Tasmanian Institute for Agriculture, University of Tasmania, Hobart, Private Bag 94, Tas 7001, Australia.

Shabala L

School of Land and Food and Tasmanian Institute for Agriculture, University of Tasmania, Hobart, Private Bag 94, Tas 7001, Australia.

Shabala S

School of Land and Food and Tasmanian Institute for Agriculture, University of Tasmania, Hobart, Private Bag 94, Tas 7001, Australia Sergey.Shabala@utas.edu.au.

MeSH

BrassicaBrassica napusCalcium-Transporting ATPasesGene Expression Regulation, PlantMembrane PotentialsMustard PlantPlant RootsPotassiumPotassium ChannelsReactive Oxygen SpeciesSalt Tolerance

Pub Type(s)

Journal Article

Language

eng

PubMed ID

27340231

Citation

Chakraborty, Koushik, et al. "Difference in Root K+ Retention Ability and Reduced Sensitivity of K+-permeable Channels to Reactive Oxygen Species Confer Differential Salt Tolerance in Three Brassica Species." Journal of Experimental Botany, vol. 67, no. 15, 2016, pp. 4611-25.

Chakraborty K, Bose J, Shabala L, et al. Difference in root K+ retention ability and reduced sensitivity of K+-permeable channels to reactive oxygen species confer differential salt tolerance in three Brassica species. J Exp Bot. 2016;67(15):4611-25.

Chakraborty, K., Bose, J., Shabala, L., & Shabala, S. (2016). Difference in root K+ retention ability and reduced sensitivity of K+-permeable channels to reactive oxygen species confer differential salt tolerance in three Brassica species. Journal of Experimental Botany, 67(15), 4611-25. https://doi.org/10.1093/jxb/erw236

Chakraborty K, et al. Difference in Root K+ Retention Ability and Reduced Sensitivity of K+-permeable Channels to Reactive Oxygen Species Confer Differential Salt Tolerance in Three Brassica Species. J Exp Bot. 2016;67(15):4611-25. PubMed PMID: 27340231.

* Article titles in AMA citation format should be in sentence-case

TY - JOUR T1 - Difference in root K+ retention ability and reduced sensitivity of K+-permeable channels to reactive oxygen species confer differential salt tolerance in three Brassica species. AU - Chakraborty,Koushik, AU - Bose,Jayakumar, AU - Shabala,Lana, AU - Shabala,Sergey, Y1 - 2016/06/23/ PY - 2016/6/25/entrez PY - 2016/6/25/pubmed PY - 2017/11/7/medline KW - H+-ATPase KW - ROS detoxification KW - ion homeostasis KW - membrane potential KW - potassium retention KW - sodium exclusion KW - tissue tolerance. SP - 4611 EP - 25 JF - Journal of experimental botany JO - J Exp Bot VL - 67 IS - 15 N2 - Brassica species are known to possess significant inter and intraspecies variability in salinity stress tolerance, but the cell-specific mechanisms conferring this difference remain elusive. In this work, the role and relative contribution of several key plasma membrane transporters to salinity stress tolerance were evaluated in three Brassica species (B. napus, B. juncea, and B. oleracea) using a range of electrophysiological assays. Initial root growth assay and viability staining revealed that B. napus was most tolerant amongst the three species, followed by B. juncea and B. oleracea At the mechanistic level, this difference was conferred by at least three complementary physiological mechanisms: (i) higher Na(+) extrusion ability from roots resulting from increased expression and activity of plasma membrane SOS1-like Na(+)/H(+) exchangers; (ii) better root K(+) retention ability resulting from stress-inducible activation of H(+)-ATPase and ability to maintain more negative membrane potential under saline conditions; and (iii) reduced sensitivity of B. napus root K(+)-permeable channels to reactive oxygen species (ROS). The last two mechanisms played the dominant role and conferred most of the differential salt sensitivity between species. Brassica napus plants were also more efficient in preventing the stress-induced increase in GORK transcript levels and up-regulation of expression of AKT1, HAK5, and HKT1 transporter genes. Taken together, our data provide the mechanistic explanation for differential salt stress sensitivity amongst these species and shed light on transcriptional and post-translational regulation of key ion transport systems involved in the maintenance of the root plasma membrane potential and cytosolic K/Na ratio as a key attribute for salt tolerance in Brassica species. SN - 1460-2431 UR - https://www.unboundmedicine.com/medline/citation/27340231/Difference_in_root_K+_retention_ability_and_reduced_sensitivity_of_K+_permeable_channels_to_reactive_oxygen_species_confer_differential_salt_tolerance_in_three_Brassica_species_ DB - PRIME DP - Unbound Medicine ER -

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Difference in root K+ retention ability and reduced sensitivity of K+-permeable channels to reactive oxygen species confer differential salt tolerance in three Brassica species.J Exp Bot. 2016 08; 67(15):4611-25.JE