Transcription Factor TaMYB30 Activates Wheat Wax Biosynthesis

Abstract

The waxy cuticle covers a plant’s aerial surface and contributes to environmental adaptation in land plants. Although past decades have seen great advances in understanding wax biosynthesis in model plants, the mechanisms underlying wax biosynthesis in crop plants such as bread wheat remain to be elucidated. In this study, wheat MYB transcription factor TaMYB30 was identified as a transcriptional activator positively regulating wheat wax biosynthesis. The knockdown of TaMYB30 expression using virus-induced gene silencing led to attenuated wax accumulation, increased water loss rates, and enhanced chlorophyll leaching. Furthermore, TaKCS1 and TaECR were isolated as essential components of wax biosynthetic machinery in bread wheat. In addition, silencing TaKCS1 and TaECR resulted in compromised wax biosynthesis and potentiated cuticle permeability. Importantly, we showed that TaMYB30 could directly bind to the promoter regions of TaKCS1 and TaECR genes by recognizing the MBS and Motif 1 cis-elements, and activate their expressions. These results collectively demonstrated that TaMYB30 positively regulates wheat wax biosynthesis presumably via the transcriptional activation of TaKCS1 and TaECR.

Chemical and Transcriptomic Analyses of Leaf Cuticular Wax Metabolism in Ammopiptanthus mongolicus under Osmotic Stress

“…Similar results were reported for associated shrubs, T. mongolica, and Z. xanthoxylum [29]. In contrast, the cuticular wax of rice and wheat leaves is primarily composed of 2-alcohols [42,43]. Another wax analysis for five Dianthus species revealed that C 28 1-alcohol and diketones were the major components forming the platelet-shaped and the tubular wax crystal, respectively [44].…”

“…The measurement of total wax revealed that the content in non-stressed leaves was 11.09 µg/cm 2 (Figure 2A). Compared with reported model plants and crops, the wax content in A. mongolicus leaves was approximately eight-fold of that of Arabidopsis leaves [41] and about twice that of rice and wheat leaves [42,43]. These results suggested that A. mongolicus, as a shrub adapted to desert, had a higher level of wax accumulation compared to plants thriving in mild environments, providing important support for environment adaptation through cuticle lipid structures.…”

Wheat MIXTA-like Transcriptional Activators Positively Regulate Cuticular Wax Accumulation

“…Although cuticular wax accumulation in bread wheat is less understood compared with A. thaliana , wheat transcription factors governing wax accumulation have been increasingly identified in recent years. For instance, wheat AP2/ERF transcription factor TaWIN1/SHN1, basic helix-loop-helix (bHLH) transcription factor TaKPAB1, and MYB transcription factors TaMYB30, TaMYB31, and TaEPBM1/MYB96 function as positive regulators of cuticular wax accumulation [ 85 , 86 , 87 , 88 , 89 , 90 ].…”

Wheat Transcriptional Corepressor TaTPR1 Suppresses Susceptibility Genes TaDND1/2 and Potentiates Post-Penetration Resistance against Blumeria graminis forma specialis tritici

“…For the BSMV-mediated gene silencing assay, antisense fragments of TaTPR1.1, TaTPR1.2, TaDND1, TaDND2.1, and TaDND2.2 were cloned into the pCa-γbLIC vector using the primers 5 ′ -AAGGAAGTTTAGCGGGTAGCTATGGCTCTGC-3 ′ /5 ′ -AACCACCACCACCG TTGGACCCTTTCAACCTGCAC-3 ′ , 5 ′ -AAGGAAGTTTAGTGCGAACAACTTGTTTGG-3 ′ /5 ′ -AACCACCACCACCGTTGGTTGGATGACAAATCCCA-3 ′ , 5 ′ -AAGGAAGTTTACAT AAGCAAAGGCGCCATTG-3 ′ /5 ′ -AACCACCACCACGTTCATTGCCTCTCATATTGCA-3 ′ , 5 ′ -AAGGAAGTTTAGCCCGATCGCCGCCAGCCG-3 ′ /5 ′ -AACCACCACCACCGTGAC CGACCTCTCGGCGTCG-3 ′ , and 5 ′ -AAGGAAGTTTAGCCCCAGCCCCAGCTGCTG-3 ′ / 5 ′ -AACCACCACCACCGTGCTCTCCACGCGCTCGTCG-3 ′ . The BSMV-mediated gene silencing assay and microcolony index (MI) analysis were performed as described previously [56]. At least 2000 wheat-Bgt interaction sites were counted in one experiment for each treatment, and three independent biological replicates were statistically analyzed (t-test; * p < 0.05, ** p < 0.01) for each treatment.…”