Ethylene mediates dichromate‐induced inhibition of primary root growth by altering AUX1 expression and auxin accumulation in Arabidopsis thaliana |
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| Authors: | Abdul Wakeel Imran Ali Sakila Upreti Azizullah Azizullah Bohan Liu Ali Raza Khan Linli Huang Minjie Wu Yinbo Gan |
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| Affiliation: | 1. Zhejiang Key Lab of Crop Germplasm, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China;2. Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Pakistan;3. Department of Botany, Kohat University of Science and Technology, Kohat, Pakistan |
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| Abstract: | The hexavalent form of chromium Cr(VI)] causes a major reduction in yield and quality of crops worldwide. The root is the first plant organ that interacts with Cr(VI) toxicity, which inhibits primary root elongation, but the underlying mechanisms of this inhibition remain elusive. In this study, we investigate the possibility that Cr(VI) reduces primary root growth of Arabidopsis by modulating the cell cycle‐related genes and that ethylene signalling contributes to this process. We show that Cr(VI)‐mediated inhibition of primary root elongation was alleviated by the ethylene perception and biosynthesis antagonists silver and cobalt, respectively. Furthermore, the ethylene signalling defective mutants (ein2‐1 and etr1‐3) were insensitive, whereas the overproducer mutant (eto1‐1) was hypersensitive to Cr(VI). We also report that high levels of Cr(VI) significantly induce the distribution and accumulation of auxin in the primary root tips, but this increase was significantly suppressed in seedlings exposed to silver or cobalt. In addition, genetic and physiological investigations show that AUXIN‐RESISTANT1 (AUX1) participates in Cr(VI)‐induced inhibition of primary root growth. Taken together, our results indicate that ethylene mediates Cr(VI)‐induced inhibition of primary root elongation by increasing auxin accumulation and polar transport by stimulating the expression of AUX1. |
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| Keywords: | Arabidopsis thaliana AUX1 auxin chromium Cr(VI) ethylene primary root growth |
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