A lack of mitochondrial alternative oxidase compromises capacity to recover from severe drought stress

• DOI: 10.1111/ppl.12059
• Publication Date: 2013-04-13T15:14:41Z
• Authors: Jia Wang; Greg C. Vanlerberghe
• Keywords: Alternative oxidase; Drought stress

Alternative oxidase (AOX) constitutes a nonenergy conserving branch of the mitochondrial electron transport chain. AOX activity may be important to avoid reactive oxygen species (ROS) generation by chain, particularly during abiotic stress. We compared leaf AOX1a transcript and protein amounts in wild-type (WT) Nicotiana tabacum plants experiencing mild severe drought. Mild moderate drought resulted progressive modest increase amount, accompanied increased expression different ROS-scavenging components. Under these conditions, transgenic with suppressed due an RNA interference construct, were not compromised their ability manage ROS load prevent cellular damage. Severe stress, when combined irradiance, strongly amount WT tobacco this coincided total respiration and, despite further induction systems, some evidence lacking suffered more damage than at most stage, found downregulate rather upregulate level several At could still recover rapidly after rewatering, but recoverability knockdown was compromised.