A GDSL‐motif esterase/acyltransferase/lipase is responsible for leaf water retention in barley

Abstract

The hydrophobic cuticle covers the surface of the most aerial organs of land plants.The barley mutant eceriferum-zv (cer-zv), which is hypersensitive to drought, is unable to accumulate a sufficient quantity of cutin in its leaf cuticle. The mutated locus has been mapped to a 0.02 cM segment in the pericentromeric region of chromosome 4H. As a map-based cloning approach to isolate the gene was therefore considered unlikely to be feasible, a comparison was instead made between the transcriptomes of the mutant and the wild type. In conjunction with extant genomic information, on the basis of predicted functionality, only two genes were considered likely to encode a product associated with cutin formation. When eight independent cer-zv mutant alleles were resequenced with respect to the two candidate genes, it was confirmed that the gene underlying the mutation in each allele encodes a Gly-Asp-Ser-Leu (GDSL)-motif esterase/acyltransferase/lipase. The gene was transcribed in the epidermis, and its product was exclusively deposited in cell wall at the boundary of the cuticle in the leaf elongation zone, coinciding with the major site of cutin deposition. CER-ZV is speculated to function in the deposition of cutin polymer. Its homologs were found in green algae, moss, and euphyllophytes, indicating that it is highly conserved in plant kingdom. K E Y W O R D Sabiotic stress, cell walls, cuticle/waxes, drought/water stress *These authors contributed equally to this work.--

Ecophysiology with barley eceriferum (cer) mutants: the effects of humidity and wax crystal structure on yield and vegetative parameters

“…Likewise, two cer.yl mutants obtained from the Nordic Genetic Resource Center, belonging to the uppermost internode plus leaf sheath and spike cer group, did not stain with TB ( Supplementary Data Fig. S1 ) as expected, in contrast to results reported by Li et al (2017) , working with the Bowman-derivative, near-isogenic line BW143.…”

“…Except for cer.zv and . ym mutants determining a GDSL-motif esterase/acyltransferase/lipase gene ( Li et al , 2017 ), none of the other 29 tested cer mutants and three wlt mutants were stained by TB. Although accounting for only a small percentage of water loss, the predominant epidermal pavement cells have the same type of wax crystals in analogous amounts to the stomates.…”

“…Recently, mutations of two of the latter, Cer.zv and . ym , have been localized to the same gene, a GDSL-motif esterase/acyltransferase/lipase ( Li et al , 2017 ) indispensable for synthesis of the cuticle’s structural component, the cutin polymer, which, together with its embedded waxes, is required for water retention. Thus, 28 of the Cer genes affect leaf blades and are referred to hereafter as barley Cer leaf genes.…”

Differential expression between drought-tolerant and drought-sensitive sugarcane under mild and moderate water stress as revealed by a comparative analysis of leaf transcriptome

“…The sensitive genotype had higher expression of At5g55050 encoding GDSL-lipase-like protein than the tolerant genotype. In barley, a GDSL motif lipase played roles in leaf water retention associated with deposition of cutin polymer in the leaves (Li et al, 2017). The results suggest that both genotypes likely have different non-stomatal mechanisms.…”

Global Role of Crop Genomics in the Face of Climate Change

“…Similarly, a domestication associated NAC gene controlling pod shattering resistance has been identified in soybean ( Dong et al, 2014 ). Advances in genomics provided the necessary platform to facilitate gene discovery and identification such as detection of genes associated with non-brittle rachis in pasta wheat and seed filling in maize using whole-genome sequencing ( Sosso et al, 2015 ; Avni et al, 2017 ); smooth awn in barley using genotyping by sequencing ( Milner et al, 2019 ); seed quality in soybean; and cutin responsible for water retention in barley using RNA sequencing ( Li et al, 2012 , 2017a ; Gao et al, 2018 ).…”