Transcriptome Analysis Provides Insights into Avenanthramide Biosynthesis in Oats under Methyl Jasmonate and Abscisic Acid Cotreatment

Avenanthramides are phenolic alkaloid derivatives uniquely
found
in oats (Avena sativa L.). We conducted
transcriptomic analysis to investigate the global changes of gene
expression in oat seedlings cotreated with methyl jasmonate (MJ) and
abscisic acid (ABA). The cotreatment significantly enhanced avenanthramide
accumulation in oat seedlings, reaching 1171.7 mg/kg fresh weight,
representing a 5.5-fold increase compared to the 4 day control sample
(221.5 mg/kg FW). A total of 4841 genes were differentially expressed,
including 1921 upregulated and 2920 downregulated genes compared to
untreated controls. Co-treatment upregulated genes encoding phenylalanine
ammonia-lyase (PAL), 4-coumarate-CoA ligase (4CL), caffeoyl-CoA O-methyltransferase (CCoAOMT), and hydroxycinnamoyl-CoA:hydroxyanthranilate N-hydroxycinnamoyl transferase (HHT) enzymes, along with
98 transcription factors from MYB, bHLH, HSF, WRKY, bZIP, and ERF
families. These results suggest that MJ and ABA cotreatment modulates
the expression of key biosynthetic and regulatory genes involved in
avenanthramide production in oat seedlings, offering valuable insights
for enhancing the nutraceutical value of oats.

燕麦酰胺（avenanthramides）是一类仅存在于普通燕麦（Avena sativa L.）中的酚类生物碱衍生物。本研究通过转录组分析，探究了经茉莉酸甲酯（methyl jasmonate，MJ）与脱落酸（abscisic acid，ABA）共同处理的燕麦幼苗的基因表达全局变化。该共同处理显著提升了燕麦幼苗中燕麦酰胺的积累量，达到1171.7 mg/kg鲜重，较4天对照组样本（221.5 mg/kg FW）提升了5.5倍。与未处理对照组相比，共鉴定出4841个差异表达基因，其中1921个基因上调、2920个基因下调。共同处理上调了编码苯丙氨酸解氨酶（phenylalanine ammonia-lyase，PAL）、4-香豆酸-CoA连接酶（4-coumarate-CoA ligase，4CL）、咖啡酰-CoA O-甲基转移酶（caffeoyl-CoA O-methyltransferase，CCoAOMT）以及羟基肉桂酰-CoA:羟基邻氨基苯甲酸酯N-羟基肉桂酰转移酶（hydroxycinnamoyl-CoA:hydroxyanthranilate N-hydroxycinnamoyl transferase，HHT）的基因，同时还上调了来自MYB、bHLH、HSF、WRKY、bZIP及ERF家族的98个转录因子。上述结果表明，茉莉酸甲酯与脱落酸共同处理可调控燕麦幼苗中参与燕麦酰胺生物合成的关键基因及调控基因的表达，为提升燕麦的营养保健价值提供了重要参考。