Aluminium (Al) stress is a major limiting factor for worldwide crop production in acid soils. In Arabidopsis thaliana, the TAA1-dependent local auxin biosynthesis in the root-apex transition zone (TZ), the major perception site for Al toxicity, is crucial for the Al-induced root-growth inhibition, while the mechanism underlying Al-regulated auxin accumulation in the TZ is not fully understood. In the present study, the role of auxin transport in Al-induced local auxin accumulation in the TZ and root-growth inhibition was investigated. Our results showed that PIN-FORMED (PIN) proteins such as PIN1, PIN3, PIN4 and PIN7 and AUX1/LAX proteins such as AUX1, LAX1 and LAX2 were all ectopically up-regulated in the root-apex TZ in response to Al stress and coordinately regulated local auxin accumulation in the TZ and root-growth inhibition. The ectopic up-regulation of PIN1 in the TZ under Al stress was regulated by both ethylene and auxin, with auxin signalling acting downstream of ethylene. Al-induced PIN1 up-regulation and auxin accumulation in the root-apex TZ was also regulated by the calossin-like protein BIG. Together, our results provide insight into how Al stress induces local auxin accumulation in the TZ and root-growth inhibition through the local regulation of auxin transport.

• Klíčová slova
• PIN1, aluminium, auxin transport, root growth, root-apex transition zone,
• MeSH
• Arabidopsis účinky léků   genetika   růst a vývoj   fyziologie   MeSH
• biologický transport MeSH
• ethyleny metabolismus   MeSH
• fyziologický stres MeSH
• hliník toxicita   MeSH
• kořeny rostlin účinky léků   genetika   růst a vývoj   metabolismus   MeSH
• kyseliny indoloctové metabolismus   MeSH
• membránové transportní proteiny genetika   metabolismus   MeSH
• proteiny huseníčku genetika   metabolismus   MeSH
• proteiny vázající kalmodulin genetika   metabolismus   MeSH
• regulace genové exprese u rostlin MeSH
• regulátory růstu rostlin metabolismus   MeSH
• upregulace MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• BIG protein, Arabidopsis MeSH Prohlížeč
• ethylene MeSH Prohlížeč
• ethyleny MeSH
• hliník MeSH
• kyseliny indoloctové MeSH
• membránové transportní proteiny MeSH
• PIN1 protein, Arabidopsis MeSH Prohlížeč
• proteiny huseníčku MeSH
• proteiny vázající kalmodulin MeSH
• regulátory růstu rostlin MeSH

Polar auxin transport plays a pivotal role in plant growth and development. PIN-FORMED (PIN) auxin efflux carriers regulate directional auxin movement by establishing local auxin maxima, minima, and gradients that drive multiple developmental processes and responses to environmental signals. Auxin has been proposed to modulate its own transport by regulating subcellular PIN trafficking via processes such as clathrin-mediated PIN endocytosis and constitutive recycling. Here, we further investigated the mechanisms by which auxin affects PIN trafficking by screening auxin analogs and identified pinstatic acid (PISA) as a positive modulator of polar auxin transport in Arabidopsis (Arabidopsis thaliana). PISA had an auxin-like effect on hypocotyl elongation and adventitious root formation via positive regulation of auxin transport. PISA did not activate SCFTIR1/AFB signaling and yet induced PIN accumulation at the cell surface by inhibiting PIN internalization from the plasma membrane. This work demonstrates PISA to be a promising chemical tool to dissect the regulatory mechanisms behind subcellular PIN trafficking and auxin transport.

• MeSH
• Arabidopsis účinky léků   metabolismus   MeSH
• biologický transport účinky léků   MeSH
• buněčná membrána účinky léků   metabolismus   MeSH
• endocytóza * účinky léků   MeSH
• fenotyp MeSH
• fenylacetáty farmakologie   MeSH
• gravitropismus účinky léků   MeSH
• hypokotyl účinky léků   růst a vývoj   MeSH
• kořeny rostlin účinky léků   růst a vývoj   MeSH
• kyseliny indoloctové metabolismus   MeSH
• proteiny huseníčku metabolismus   MeSH
• signální transdukce MeSH
• výhonky rostlin metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• fenylacetáty MeSH
• kyseliny indoloctové MeSH
• phenylacetic acid MeSH Prohlížeč
• pinstatic acid MeSH Prohlížeč
• proteiny huseníčku MeSH