Enhanced Polar Auxin Transport in Tomato Polycotyledon Mutant Seems to be Related to Glutathione Levels

• Published in: Journal of plant growth regulation Vol. 40; no. 2; pp. 761 - 773
• Main Authors: Nongmaithem, Sapana, Ponukumatla, Rachana, Sreelakshmi, Yellamaraju, Frasse, Pierre, Bouzayen, Mondher, Sharma, Rameshwar
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.04.2021; Springer Nature B.V; Springer Verlag
• Subjects: Acids; Agriculture; Arabidopsis; auxins; Benzoic acid; Biochemistry, Molecular Biology; Biomedical and Life Sciences; Buthionine sulfoximine; DNA microarrays; Elongation; Gene expression; glutamic acid; Glutathione; Life Sciences; metabolism; microarray technology; Mutants; p-Hydroxyphenylacetic acid; phenotype; Phenotypes; Pin1 protein; Plant Anatomy/Development; Plant growth; Plant Physiology; Plant Sciences; root growth; seedling growth; Seedlings; Tips; Tomatoes; Vegetal Biology; PAT inhibitors; Auxin; Triiodobenzoic acid; Tomato; Polar auxin transport; Glutathione
• ISSN: 0721-7595; 1435-8107
• DOI: 10.1007/s00344-020-10139-8

Glutathione-dependent root growth in Arabidopsis is linked to polar auxin transport (PAT). Arabidopsis mutants with reduced glutathione (GSH) levels also show reduced PAT. To gain an insight into the relationship between PAT and GSH level, we analyzed tomato polycotyledon mutant, pct1-2, which has enhanced PAT. Microarray analysis of gene expression in pct1-2 mutant revealed underexpression of several genes related to glutamate and glutathione metabolism. In consonance with microarray analysis, enzymatic as well as in vivo assay revealed higher glutathione levels in the early phase of pct1-2 seedling growth than WT. The inhibition of auxin transport by 2,3,5-triiodobenzoic acid (TIBA) reduced both GSH level and PIN1 expression in pct1-2 root tips . The reduction of in vivo GSH accumulation in pct1-2 root tips by buthionine sulfoximine (BSO) stimulated elongation of the short root of pct1-2 mutant akin to TIBA. The rescue of the short root phenotype of the pct1-2 mutant was restricted to TIBA and BSO. The other auxin transport inhibitors 1- N -naphthylphthalamic acid (NPA), 2-[4-(diethylamino)-2-hydroxybenzoyl] benzoic acid (BUM), 3-chloro-4-hydroxyphenylacetic acid (CHPAA), brefeldin and gravacin inhibited root elongation in both WT and pct1-2 mutant. Our results indicate a relationship between PAT and GSH levels in tomato akin to Arabidopsis. Our work also highlights that TIBA rescues the short root phenotype of the pct1-2 mutant by acting on a PAT component distinct from the site of action of other PAT inhibitors.