Mitochondrial pyruvate dehydrogenase contributes to auxin-regulated organ development

Iwai Ohbayashi, Shaobai Huang, Hidehiro Fukaki, Xiaomin Song, Song Sun, Miyo Terao Morita, Masao Tasaka, A. Harvey Millar, Masahiko Furutani

研究成果: Article同行評審

32 引文 斯高帕斯(Scopus)


Pyruvate dehydrogenase is the first enzyme (E1) of the PDH complex (PDC). This multienzyme complex contains E1, E2, and E3 components and controls the entry of carbon into the mitochondrial tricarboxylic acid cycle to enable cellular energy production. The E1 component of the PDC is composed of an E1a catalytic subunit and an E1b regulatory subunit. In Arabidopsis (Arabidopsis thaliana), there are two mitochondrial E1a homologs encoded by IAA-CONJUGATE-RESISTANT 4 (IAR4) and IAR4-LIKE (IAR4L), and one mitochondrial E1b homolog. Although IAR4 was reported to be involved in auxin conjugate sensitivity and auxin homeostasis in root development, its precise role remains unknown. Here, we provide experimental evidence that mitochondrial PDC E1 contributes to polar auxin transport during organ development. We performed genetic screens for factors involved in cotyledon development and identified an uncharacterized mutant, macchi-bou 1 (mab1). MAB1 encodes a mitochondrial PDC E1b subunit that can form both a homodimer and a heterodimer with IAR4. The mab1 mutation impaired MAB1 homodimerization, reduced the abundance of IAR4 and IAR4L, weakened PDC enzymatic activity, and diminished mitochondrial respiration. A metabolomics analysis showed significant changes in metabolites including amino acids in mab1 and, in particular, identified an accumulation of Ala. These results suggest that MAB1 is a component of the Arabidopsis mitochondrial PDC E1. Furthermore, in mab1 mutants and seedlings where the TCA cycle was pharmacologically blocked, we found reduced abundance of the PIN-FORMED (PIN) auxin efflux carriers, possibly due to impaired PIN recycling and enhanced PIN degradation in vacuoles.

頁(從 - 到)896-909
期刊Plant Physiology
出版狀態Published - 2019 6月

All Science Journal Classification (ASJC) codes

  • 生理學
  • 遺傳學
  • 植物科學


深入研究「Mitochondrial pyruvate dehydrogenase contributes to auxin-regulated organ development」主題。共同形成了獨特的指紋。