Abstract
BackgroundChickpea is an important legume and is moderately tolerant to salinity stress during the growing season. However, the level and mechanisms for salinity tolerance can vary among accessions and cultivars. A large family of CaRab-GTP genes, previously identified in chickpea, is homologous to intracellular vesicle trafficking superfamily genes that play essential roles in response to salinity stress in plants.ResultsTo determine which of the gene family members are involved in the chickpea salt response, plants from six selected chickpea accessions (Genesis 836, Hattrick, ICC12726, Rupali, Slasher and Yubileiny) were exposed to salinity stress and expression profiles resolved for the major CaRab-GTP gene clades after 5, 9 and 15 days of salt exposure. Gene clade expression profiles (using degenerate primers targeting all members of each clade) were tested for their relationship to salinity tolerance measures, namely plant biomass and Na+ accumulation. Transcripts representing 11 out of the 13 CaRab clades could be detected by RT-PCR, but only six (CaRabA2, −B, −C, −D, −E and −H) could be quantified using qRT-PCR due to low expression levels or poor amplification efficiency of the degenerate primers for clades containing several gene members. Expression profiles of three gene clades, CaRabB, −D and −E, were very similar across all six chickpea accessions, showing a strongly coordinated network. Salt-induced enhancement of CaRabA2 expression at 15 days showed a very strong positive correlation (R2 = 0.905) with Na+ accumulation in leaves. However, salinity tolerance estimated as relative plant biomass production compared to controls, did not correlate with Na+ accumulation in leaves, nor with expression profiles of any of the investigated CaRab-GTP genes.ConclusionA coordinated network of CaRab-GTP genes, which are likely involved in intracellular trafficking, are important for the salinity stress response of chickpea plants.
Highlights
Chickpea is an important legume and is moderately tolerant to salinity stress during the growing season
All six chickpea germplasm accessions showed some form of growth impairment in the presence of NaCl, demonstrated by decreased fresh weight (FW) and dry weight (DW) (Fig. 1), and visual symptoms including chlorosis, browning and senescence (Additional file 1, Fig. S1-S2)
In the latest model [10], RabD protein is associated with the Rough Endoplasmic Reticulum (RER), while RabB and RabA are localized in the Golgi and transGolgi network/Early endosome (TGN/EE), respectively
Summary
Chickpea is an important legume and is moderately tolerant to salinity stress during the growing season. A large family of CaRab-GTP genes, previously identified in chickpea, is homologous to intracellular vesicle trafficking superfamily genes that play essential roles in response to salinity stress in plants. GDP/GTP Exchange Proteins or Factors (GEPs or GEFs), including Transport Protein Particle II (TRAPPII) and GDP Dissociation Inhibitors (GDIs), enhance and inhibit the transition process between the two forms, respectively [10]. GDIs retain Rab-GTPs in their GDP-bound form, which leads to dissociation of the Rab-GTP from its membrane and this, along with Rab Escort Proteins (REPs) and prenylation of Rab-GTPs, enables recycling and re-targeting of the Rab-GTP to new membranes for multiple rounds of vesicle transport [10,11,12,13,14,15,16]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
