Signalling Interactions in Flooding Tolerance

Abstract

Flooding is a frequently encountered abiotic stress that is extremely detrimental to plant growth and development, metabolism, function, and yield. Water severely restricts gas exchange impeding photosynthesis and respiration, and ultimately leads to an energy crisis that can prove fatal. Most land plants are extremely sensitive to prolonged waterlogging and submergence. However, some plant species are at home in frequently flooded environments. This is linked to a set of adaptive traits and metabolic adjustments that confer the ability to either avoid or cope with flooding‐induced oxygen deprivation. Here, we outline the current knowledge on these morphological, anatomical, and metabolic tolerance traits, and how they facilitate flooding survival. Furthermore, we elaborate on the molecular processes and signalling mechanisms that regulate some of these traits. A better understanding of these tolerance attributes is essential in the quest towards the generation of climate resilient crops in an era of global warming and increased food demand.

Lysigenous aerenchyma formation: responsiveness to waterlogging in oil palm roots

“…Similarly, in maize roots, we found the up-regulation of Ca 2+ signaling-related genes encoding calmodulin under waterlogged conditions (Rajhi et al 2011). Furthermore, CAMTA4, TCTP, and CPI1 were upregulated in the primary roots after waterlogging stress for 3 d. CAMTA4, a member of the calmodulin-binding transcription activators (CAMTAs) family (Meer et al 2019), is regulated in response to calcium signals and the positive regulation is a general stress response (Benn et al 2014). In general, CAMTAs are reported in response to drought, cold, salinity, and hormones (e.g., auxin, abscisic acid, and jasmonic acid) (Benn et al 2014).…”

A Role for Auxin in Ethylene-Dependent Inducible Aerenchyma Formation in Rice Roots

“…Ethylene is involved in inducible aerenchyma formation in rice roots [4][5][6][7]. Under waterlogging, lower diffusion rates of gases to the rhizosphere enhance the ethylene accumulation in roots [8,9]. Ethylene is biosynthesized by the conversion of S-adenosylmethionine to 1-amino-cyclopropane-1-carboxylic acid (ACC) by ACC synthase (ACS) and that of ACC to ethylene by ACC oxidase (ACO) [10].…”

Two Brassica napus cultivars differ in gene expression, but not in their response to submergence

“…Two types of survival strategies have been observed to tolerate flooding (summarized in van Veen et al, 2014; Voesenek & Bailey‐Serres, 2015): (1) Several plant species avoid oxygen deficiency by multiple mechanisms that favor gas transport, such as development of adventitious roots, formation of aerenchyma in roots and leaves, gas films on leaves as well as elongational growth to restore contact to oxygen‐rich air (summarized in Voesenek & Bailey‐Serres, 2015; Mustroph et al, 2018; Yamauchi et al, 2018). This strategy is commonly referred to as the low‐oxygen escape strategy.…”