The plant cuticle, a cutin matrix embedded with and covered by wax, seals the aerial organ's surface to protect the plant against uncontrolled water loss. The cutin matrix is essential for the cuticle to function as a barrier to water loss. Recently, we identified from wild barley a drought supersensitive mutant, eibi1, which is caused by a defective cutin matrix as the result of the loss of function of HvABCG31, an ABCG full transporter. Here, we report that eibi1 epidermal cells contain lipid-like droplets, which are supposed to consist of cutin monomers that have not been transported out of the cells. The eibi1 cuticle is fragile due to a defective cutin matrix. The rice ortholog of the EIBI1 gene has a similar pattern of expression, young shoot but not flag leaf blade, as the barley gene. The model of the function of Eibi1 is discussed. The HvABCG31 full transporter functions in the export of cutin components and contributed to land plant colonization, hence also to terrestrial life evolution.
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was also localized in developing, but not in mature tissue in barley.2 Similarly, the analysis of Eibi1 expression in rice showed the presence of abundant transcripts in young shoot, but only traces in flag leaf blade, rachis and root (Fig. 2). The gene was also expressed in young caryopsis, peduncle, nodes and unelongated stem. AtABCG32/Pec1, the closest Eibi1 homolog in Arabidopsis, is expressed in all organs of the shoot with a tendency toward higher expression levels in young, expanding tissues than in older This work was supported by the “One Hundred Talents” Project of the Chinese Academy of Sciences (O827751002), the National Natural Science Foundation of China (30970449, 31170369), Genomics for Agricultural Innovation Grant TRG1004 from the Ministry of Agriculture, Forestry and Fisheries of Japan, postdoctoral Grant P10511 from the Japan Society for the Promotion of Science, the Ancell Teicher Research Foundation for Genetics and Molecular Evolution.
- ABC transporter
- Cuticular wax
- Drought resistance
ASJC Scopus subject areas
- Plant Science