Enhanced ROS scavenging and sugar accumulation contribute to drought tolerance of naturally occurring autotetraploids in Poncirus trifoliata

Abstract

Summary Tetraploids have been reported to exhibit increased stress tolerance, but the underlying molecular and physiological mechanisms remain poorly understood. In this study, autotetraploid plants were identified by screening natural seedlings of trifoliate orange ( Poncirus trifoliata ). The tetraploids exhibited different morphology and displayed significantly enhanced drought and dehydration tolerance in comparison with the diploid progenitor. Transcriptome analysis indicated that a number of stress‐responsive genes and pathways were differentially influenced and enriched in the tetraploids, in particular those coding for enzymes related to antioxidant process and sugar metabolism. Transcript levels and activities of antioxidant enzymes (peroxidase and superoxide dismutase) and sucrose‐hydrolysing enzyme (vacuolar invertase) were increased in the tetraploids upon exposure to the drought, concomitant with greater levels of glucose but lower level of reactive oxygen species ( ROS ). These data indicate that the tetraploids might undergo extensive transcriptome reprogramming of genes involved in ROS scavenging and sugar metabolism, which contributes, synergistically or independently, to the enhanced stress tolerance of the tetraploid. Our results reveal that the tetraploids take priority over the diploid for stress tolerance by maintaining a more robust system of ROS detoxification and osmotic adjustment via elevating antioxidant capacity and sugar accumulation in comparison with the diploid counterpart.

Chromosome doubling mediates superior drought tolerance in Lycium ruthenicum via abscisic acid signaling

“…Interestingly, we observed that the DEGs identified between the two ploidy levels were markedly enriched in the stress response and hormonal signal transduction GO categories; the majority of the DEGs were closely associated with ABA. These results are similar to the enrichment in proteins responsive to ABA observed in tetraploid citrus 8,49 . The significant increase in ABA content led us to focus on ABA biosynthesis and catabolism.…”

Effects of drought stress on physiology and antioxidative activity in two varieties of Cynanchum thesioides

“…Accumulation of ROS is induced by various stresses but is scavenged by other components, such as antioxidant enzymes, non-enzymatic antioxidants and secondary metabolites (Gill et al 2011;Wei et al 2019), as has been demonstrated recently in Diospyros L. (Wei et al 2015) and blackberry (Rubus sp.) (Yang et al 2015).…”

“…The balance between production and scavenging of reactive oxygen species (ROS) is disrupted in plant cells during drought stress, and this results in a variety of harmful cytological effects (Choudhury et al 2017;Verma et al 2019;Wei et al 2019). Malondialdehyde (MDA) is an indicator of lipid peroxidation and plasma membrane damage in plant cells (Mohammadi et al 2011;Maqbool et al 2017).…”

Developmentally controlled changes during Arabidopsis leaf development indicate causes for loss of stress tolerance with age

“…Several sugars have been reported to provide tolerance to harsh environments ( Rosa et al , 2009 ; Boriboonkaset et al , 2012 ; Gechev et al , 2013 ; Wei et al , 2019 ) and are linked to stress-induced ROS accumulation, where sugars act as ROS scavengers to protect cells against oxidative damage ( Bolouri-Moghaddam et al , 2010 ; Keunen et al , 2013 ; Van Den Ende and Peshev, 2013 ). Our data are consistent with those of others who found that sugars such as trehalose, maltose, myo -inositol, and mannitol play roles as protectants against oxidative stress and accumulated to lower levels in more developed leaves ( Fig.…”