Ethylene and reactive oxygen species are involved in root aerenchyma formation and adaptation of wheat seedlings to oxygen-deficient conditions

Abstract

Ethylene-mediated reactive oxygen species signalling is involved in adaptive responses of wheat seedlings to waterlogged conditions through controlling formation of lysigenous aerenchyma and expression of genes encoding ethanol fermentation enzymes in roots

Ethylene-Mediated Acclimations to Flooding Stress

“…Constitutive aerenchyma is found in both wetland and nonwetland plants and can be further enhanced by flooding (Drew et al, 2000;Yamauchi et al, 2014). In other species, waterlogging induces aerenchyma formation (Rajhi et al, 2011;Yamauchi et al, 2014). Most research on aerenchyma formation has focused on lysigenous aerenchyma, which will be discussed here.…”

Adventitious roots of wheat seedlings that emerge in oxygen-deficient conditions have increased root diameters with highly developed lysigenous aerenchyma

“…12 Non-ACC-pretreated wheat seedlings appeared to suffer severe damage under stagnant conditions before the emergence of adventitious roots, but adventitious roots that emerged in stagnant conditions were highly adapted to stagnant conditions as shown by their continued growth under stagnant conditions. 12 Together, these observations suggested that the adventitious roots emerged in stagnant conditions have some special features to adapt to oxygen-deficient conditions. In the present study, we assessed the effects of ethylene on the responses of adventitious roots to oxygen-deficient conditions.…”

“…12 The seminal root tips of wheat seedlings grown under stagnant conditions died within 3 d. Although ACC-pretreated seminal roots of wheat seedlings grown under stagnant conditions avoided root tip death, they elongated very little. 12 Non-ACC-pretreated wheat seedlings appeared to suffer severe damage under stagnant conditions before the emergence of adventitious roots, but adventitious roots that emerged in stagnant conditions were highly adapted to stagnant conditions as shown by their continued growth under stagnant conditions. 12 Together, these observations suggested that the adventitious roots emerged in stagnant conditions have some special features to adapt to oxygen-deficient conditions.…”

“…11 Similarly, pre-treatment of an ethylene precursor, 1-aminocyclopropanecarboxylic acid (ACC), enhanced the tolerance of wheat seedlings to oxygendeficient conditions. 12 Ethylene is involved in inducible aerenchyma formation in roots of some gramineous plants. [5][6][7] Recently, we demonstrated that ethylene-induced lysigenous aerenchyma formation in seminal roots helps wheat seedlings to tolerate stagnant deoxygenated conditions (which mimic Exposing roots of plants to hypoxic conditions is known to greatly improve their anoxic stress tolerance.…”

“…12 To assess the effects of ethylene on the responses of adventitious roots to oxygendeficient conditions, 11-d-old wheat (cv Bobwhite line SH 98 26) seedlings were transferred to aerated conditions with or without ACC (20 μM) treatment and grown for 2 d. Subsequently, 13-d-old seedlings were transferred to stagnant conditions and grown for 3 d (Fig. 1A).…”