Apoplastic barriers, aquaporin gene expression and root and cell hydraulic conductivity in phosphate‐limited sheepgrass plants

Abstract Background Mineral nutrient limitation affects the water flow through plants. We wanted to test on barley whether any change in root-to-shoot ratio in response to low supply of nitrogen and phosphate is accompanied by changes in root and cell hydraulic properties and involves changes in aquaporin (AQP) gene expression and root apoplastic barriers (suberin lamellae, Casparian bands). Methods Plants were grown hydroponically on complete nutrient solution or on solution containing only 3.3 % or 2.5 % of the control level of nutrient. Plants were analysed when they were 14–18 d old. Results Nutrient-limited plants adjusted water flow to an increased root-to-shoot surface area ratio through a reduction in root hydraulic conductivity (Lp) as determined through exudation analyses. Cortex cell Lp (cell pressure probe analyses) decreased in the immature but not the mature region of the main axis of seminal roots and in primary lateral roots. The aquaporin inhibitor HgCl2 reduced root Lp most in nutrient-sufficient control plants. Exchange of low-nutrient for control media caused a rapid (20–80 min) and partial recovery in Lp, though cortex cell Lp did not increase in any of the root regions analysed. The gene expression level (qPCR analyses) of five plasma membrane-localized AQP isoforms did not change in bulk root extracts, while the formation of apoplastic barriers increased considerably along the main axis of root and lateral roots in low-nutrient treatments. Conclusions Decrease in root and cortex cell Lp enables the adjustment of root water uptake to increased root-to-shoot area ratio in nutrient-limited plants. Aquaporins are the prime candidate to play a key role in this response. Modelling of water flow suggests that some of the reduction in root Lp is due to increased formation of apoplastic barriers.

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Zinc treatment of hydroponically grown barley plants causes a reduction in root and cell hydraulic conductivity and isoform-dependent decrease in aquaporin gene expression

Physiologia Plantarum ◽

10.1111/ppl.12697 ◽

2018 ◽

Vol 164 (2) ◽

pp. 176-190 ◽

Cited By ~ 13

Author(s):

Aurora Gitto ◽

Wieland Fricke

Keyword(s):

Gene Expression ◽

Hydraulic Conductivity ◽

Zinc Treatment ◽

Aquaporin Gene ◽

Hydroponically Grown

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ABA-regulation of root hydraulic conductivity and aquaporin gene- expression is crucial to the plant shoot rise caused by rhizosphere humic acids

PLANT PHYSIOLOGY ◽

10.1104/pp.15.00596 ◽

2015 ◽

pp. pp.00596.2015 ◽

Cited By ~ 22

Author(s):

Maite Olaetxea ◽

Verónica Mora ◽

Eva Bacaicoa ◽

Roberto Baigorri ◽

Maria Garnica ◽

...

Keyword(s):

Gene Expression ◽

Hydraulic Conductivity ◽

Humic Acids ◽

Root Hydraulic Conductivity ◽

Aquaporin Gene

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Nitrogen availability affects hydraulic conductivity of rice roots, possibly through changes in aquaporin gene expression

Plant and Soil ◽

10.1007/s11104-014-2070-4 ◽

2014 ◽

Vol 379 (1-2) ◽

pp. 289-300 ◽

Cited By ~ 29

Author(s):

Junko Ishikawa-Sakurai ◽

Hidehiro Hayashi ◽

Mari Murai-Hatano

Keyword(s):

Gene Expression ◽

Hydraulic Conductivity ◽

Nitrogen Availability ◽

Rice Roots ◽

Aquaporin Gene

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Faculty Opinions recommendation of Glucose shortens the life span of C. elegans by downregulating DAF-16/FOXO activity and aquaporin gene expression.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1279994.747101 ◽

2009 ◽

Author(s):

Thomas Baranski ◽

Laura Palanker Musselman

Keyword(s):

Gene Expression ◽

Life Span ◽

C Elegans ◽

Aquaporin Gene

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Respon Morfologis dan Ekspresi Gen Aquaporin pada Padi IR 64 yang Mengalami Cekaman Kekeringan pada Fase Reproduktif (Morphological Responses and Aquaporin Gene Expression in Rice IR64 under Drought Stress at the Reproductive Stage)

JURNAL BIOS LOGOS ◽

10.35799/jbl.7.2.2017.18579 ◽

2018 ◽

Vol 7 (2) ◽

Author(s):

Made Pharmawati ◽

Ni Nyoman Wirasiti ◽

Luh Putu Wrasiati

Keyword(s):

Gene Expression ◽

Drought Stress ◽

Real Time ◽

Real Time Pcr ◽

Control Plant ◽

Reproductive Stage ◽

Limiting Factors ◽

Rice Grain ◽

Aquaporin Gene ◽

Peg Treatment

Abstrak Cekaman kekeringan merupakan faktor pembatas penting bagi pertumbuhan dan produktivitas tanaman termasuk padi. Penelitian ini bertujuan menganalisis respon padi IR64 terhadap cekaman kekeringan dengan pemberian polietilen glikol (PEG) pada fase reproduktif. Penelitian juga bertujuan menganalisis ekspresi gen aquaporin akibat cekaman kekeringan. Bibit padi ditanam dalam pot dan perlakuan PEG dengan konsentrasi 108g/L (-0.25MPa) dan 178g/L (-0.52 MPa) diberikan saat munculnya panikula. Perlakuan diberikan selama 2 minggu, kemudian tanaman disiram kembali. Ekspresi gen diamati pada akhir perlakuan dengan semi kuantitatif real time PCR. Ekstraksi RNA menggunakan RNeasy plant mini kit, sedangkan sintesis cDNA menggunakan Transcriptor First Strand cDNA Kit. Hasil penelitian menunjukkan bahwa jumlah malai dan berat total malai berkurang akibat cekaman kekeringan. Persentase gabah kosong mencapai 84,6% pada perlakuan PEG-0,52 MPa, sedangkan pada perlakuan PEG -0,25 MPa persentase gabah kosong sebesar 67,8%. Pada kontrol persentase gabah kosong adalah 10,3%. Ekspresi gen OsPIP2;7 sedikit menurun pada perlakuan PEG -0,52 MPa.Kata kunci: ekspresi gen, IR64, kekeringan, padi, PEG Abstract Drought stress is one of the limiting factors of plant growth and productivity including rice. The aim of this study was to analyze responses of IR64 rice to polyethylene glycol (PEG)-induced-drought stress at the reproductive stage. This study also aimed to analyze the expression of aquaporin under drought stress. Rice seedlings were grown in pot system and PEG treatment at concentration of -0.25MPa (108g/L) and -0.52 MPa (178g/L) were given when the panicles arose. Treatments were conducted for 2 weeks, after that the plants were rewatered. Gene expression was evaluated at the end of PEG treatment using semi quantitative real time PCR. RNA was extracted using RNeasy plant mini kit, while cDNA synthesis was done using Transcriptor First Strand cDNA Kit. The results showed that the number and weight of rice ear were less in plant treated with PEG than in control. The percentage of empty rice grain reached 84.6% at PEG -0.52 MPa, while at PEG -0.25 MPa the percentage of empty grain was 67.8%. In control plant, the percentage of empty grain was 10.3%. Drought stress did not alter the expression of OsPIP2;7. Keywords: drought, gene expression, IR64, PEG, rice

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