Molecular cloning and expression analysis of Aquaporin genes in pearl millet [ Pennisetum glaucum (L) R. Br.] genotypes contrasting in their transpiration response to high vapour pressure deficits

Reddy, P S and Tharanya, M and Sivasakthi, K and Srikanth, M and Hash, C T and Kholova, J and Sharma, K K and Vadez, V (2017) Molecular cloning and expression analysis of Aquaporin genes in pearl millet [ Pennisetum glaucum (L) R. Br.] genotypes contrasting in their transpiration response to high vapour pressure deficits. Plant Science, 265. pp. 167-176. ISSN 01689452

[img] PDF - Published Version
Restricted to ICRISAT users only

Download (2MB) | Request a copy

Abstract

Pearl millet is a crop of the semi-arid tropics having high degree of genetic diversity and variable tolerance to drought stress. To investigate drought tolerance mechanism that possibly accounts for differences in drought tolerance, four recombinant inbred lines from a high resolution cross (HRC) were selected for variability in their transpiration rate (Tr) response to vapour pressure deficit (VPD) conditions. The differential Tr response of the genotypes to increased VPD conditions was used to classify the genotypes as sensitive or insensitive to high VPD. Aquaporin (AQP) genes PgPIP1;1, PgPIP1;2, PgPIP2;1, PgPIP2;3, PgPIP2;6, PgTIP1;1 and PgTIP2;2 were cloned. Phylogenetic analysis revealed that the cloned PgAQPs were evolutionarily closer to maize AQPs than to rice. PgAQP genes, including PgPIP1;1 and PgPIP2;6 in root tissue showed a significant expression pattern with higher expression in VPD-insensitive genotypes than VPD-sensitive genotypes under low VPD conditions (1.2 kPa) i.e when there is no high evaporative demand from the atmosphere. PgAQP genes (PgPIP2;1 in leaf and root tissues; PgPIP1;2 and PgTIP2;2 in leaf and PgPIP2;6 in root) followed a diurnal rhythm in leaves and roots that have either higher or lower expression levels at different time intervals. Under high VPD conditions (4.21 kPa), PgPIP2;3 showed higher transcript abundance in VPD-insensitive genotypes, and PgPIP2;1 in VPD-sensitive genotypes, while rest of the PgAQPs showed differential expression. Our current hypothesis is that these differences in the expression of AQP genes under different VPDs suggests a role of the AQPs in tuning the water transport pathways with variation between genotypes.

Item Type: Article
Divisions: Research Program : Genetic Gains
CRP: CGIAR Research Program on Dryland Cereals
Uncontrolled Keywords: Pearl millet, Molecular cloning, Aquaporins, Transpiration rate, Vapour pressure deficit, VPD-sensitive genotype, VPD-insensitive genotype, Drought tolerance
Subjects: Others > Molecular biology
Mandate crops > Millets > Pearl Millet
Others > Genetics and Genomics
Depositing User: Mr Ramesh K
Date Deposited: 26 Oct 2017 05:17
Last Modified: 26 Oct 2017 05:17
URI: http://oar.icrisat.org/id/eprint/10234
Official URL: http://dx.doi.org/10.1016/j.plantsci.2017.10.005
Projects: Blue Sky Research Project
Funders: Department of Science and Technology, Govt. of India
Acknowledgement: PSR is thankful to the Department of Science and Technology, Govt. of India, New Delhi, for research funding under the Young Scientist Scheme (SB/YS/LS-12/2013) through SERB and INSPIRE Faculty Fellowship Award (Grant No. IFA-LSPA-06). This work has been undertaken as part of the CGIAR Research Program on Dryland Cereals, and received funding from ICRISAT under the Blue Sky Research Project on “Developing crops with high productivity under high temperatures”. ICRISAT is a member of the CGIAR Consortium.
Links:

Actions (login required)

View Item View Item