Triacylglycerol (TAG) accumulation and abiotic stress tolerance are critical for woody oil crop productivity, yet their coordination remains poorly understood. Here, we characterized CcDGAT1, a diacylglycerol acyltransferase 1 gene from hickory (Carya cathayensis) that links oil accumulation with aluminum (Al) tolerance. CcDGAT1 was highly expressed in developing kernels and vegetative tissues and was strongly induced by Al stress. CcDGAT1 overexpression increased total oil content and unsaturated fatty acid levels and enhanced Al tolerance, as shown by improved membrane integrity, root growth, and biomass. Under Al stress, CcDGAT1 overexpression promoted the accumulation of 18:2/18:3‐containing TAGs while reducing 18:2/18:3‐enriched membrane lipid pools. Consistent with this protective role, transient silencing of CcDGAT1 in hickory roots aggravated Al‐induced lipid peroxidation and electrolyte leakage. Dual‐luciferase, yeast one‐hybrid, and electrophoretic mobility shift assays demonstrated that CcATML1 and CcWRKY11a directly activate CcDGAT1 transcription. Overexpression of these transcription factors increased CcDGAT1 expression, fatty acid content, membrane integrity, and Al tolerance. Together, these findings establish CcDGAT1 as a functional oil‐promoting DGAT1 in hickory and support a model in which CcDGAT1‐associated lipid remodeling contributes to Al‐stress protection. The CcATML1/CcWRKY11a‐CcDGAT1 module further provides a transcriptional framework for linking lipid metabolism with stress resilience in woody oil crops.
Shan Zheng, Wenchao Chen, Jiaqi Zhang et al.· New Phytologist· 0 citations
B-BOX (BBX) transcription factors regulate plant growth and drought tolerance, whereas comprehensive characterization of BBX gene families in gymnosperms remains scarce. We identified 13 TgBBXs in Torreya grandis at the genome-wide level, and phylogenetic analysis grouped them into five subgroups consistent with the conserved classification of plant BBX members. Promoter analysis revealed abundant light hormone and stress related cis-elements, and the TgBBXs displayed distinct expression patterns across various tissues and reproductive developmental stages. PEG-triggered drought decreased leaf chlorophyll, accompanied by increased root H2O2, APX and POD levels. Transcriptome data showed obvious tissue-specific expression and organ-dependent drought responses; most of TgBBX5–TgBBX12 were continuously upregulated in leaves under PEG treatment, whereas several members declined in roots. WGCNA further indicated that the MEturquoise module, which contained most TgBBXs, was closely associated with chlorophyll accumulation and antioxidant responses. Among these genes, TgBBX2, TgBBX7, and TgBBX13 with module membership over 0.9 are putative hub genes, and their associated genes enrich in photosynthesis and antioxidant pathways. This study systematically characterized the BBX family in T. grandis for the first time and identified key drought-responsive genes, providing valuable resources for drought-tolerant molecular breeding of this economically important gymnosperm.
Weijie Chen, Xuanzi Zhang, Xiao Liu et al.· Horticulturae· 0 citations