太白贝母种子低温萌发过程中C3H基因家族鉴定及表达分析

Identification and expression analysis of C3H gene family during low-temperature germination in seeds of Fritillaria taipaiensis

关键词:  太白贝母，C3H，种子萌发，生物信息分析，表达模式

Key words:  Fritillaria taipaiensis, C3H, seed germination, bioinformatics analysis, expression pattern

摘要:

为解析C3H基因在太白贝母种子萌发过程中的作用，该研究基于低温萌发转录组数据，通过生物信息学的方法对太白贝母C3H基因家族进行系统鉴定及表达分析，筛选出5个低温高表达候选基因并解析其对GA3和ABA的响应机制。结果表明：（1）C3H家族65个成员中7个为稳定亲水蛋白、58个不稳定，蛋白长度差异显著（197~1 451 aa），仅FtC3H43和FtC3H50定位于叶绿体/内质网，其余位于细胞核。（2）保守基序分析发现，Motif1和Motif3普遍存在C3H蛋白中；系统进化分析结果显示，196条C3H蛋白被聚类为5个不同的分支，标记为I到Ⅴ，太白贝母C3H成员与拟南芥和水稻表现出较近的亲缘关系。（3）GA3处理下，FtC3H22和FtC3H35在A-C时期促进萌发，FtC3H40在A期、FtC3H46在E期响应调控；ABA处理时FtC3H46显著上调，而FtC3H22和FtC3H35下调，推测FtC3H46参与ABA介导的抗寒途径，FtC3H22和FtC3H35则正向调控萌发。该研究结果揭示了C3H蛋白家族在太白贝母种子萌发过程中的重要作用和复杂调控机制。

Abstract:

This study systematically investigated the role of C3H genes in?Fritillaria taipaiensis?seed germination by integrating low-temperature germination transcriptome data and bioinformatics approaches. Five cold-inducible candidate genes were identified and characterized to elucidate their regulatory mechanisms in response to gibberellic acid (GA?) and abscisic acid (ABA). The results were as follows:（1）Among 65 identified C3H family members, seven were classified as stable hydrophilic proteins, whereas 58 exhibited instability, with significant variation in protein length (197–1 451 amino acids). Subcellular localization predictions indicated that only FtC3H43 and FtC3H50 were localized to chloroplasts/endoplasmic reticulum, while the majority were nuclear-localized.（2）Conserved motif analysis revealed the ubiquitous presence of Motif1 and Motif3 across C3H family members. Phylogenetic analysis clustered 196 C3H proteins into five distinct clades (I–V), with?F. taipaiensis?C3Hs showing close evolutionary relationships to those in?Arabidopsis?and rice.（3）Under GA? treatment,?FtC3H22?and?FtC3H35?promoted germination during early-to-mid stages (A–C), while?FtC3H40?and?FtC3H46?exhibited stage-specific expression at stages A and E, respectively. ABA treatment significantly upregulated?FtC3H46?but downregulated?FtC3H22?and?FtC3H35, suggesting?FtC3H46?may mediate ABA-dependent cold stress responses, whereas?FtC3H22?and?FtC3H35?play positive roles in germination regulation.