花烟草（Nicotianaalata）叶绿素酶基因NalaCLH2的克隆与表达模式分析

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中图分类号： S682.1+9：（2785 文献标识号：A 文章编号：1001-4942（2025）08-0015-09

AbstractChlorophylase facilitates the first step of chlorophyll degradation and play key roles in the senescence of leaves，flowering and fruit ripening.To elucidate the function of chlorophyllase2（CLH2）gene in Nicotiana alata，the homologous cloning method was used to clone CLH2 gene from Nicotiana alata and the bioinformatics analysis was conducted.Furthermore，real-time fluorescence quantitative PCR was used to analyze the tissue-specific expression of this gene and the expression characteristics of Nicotiana alata seedlings treated with abiotic stresses and different hormones.The results showed that the open reading frame （ORF）of NalaCLH2 was 960bp （GenBank accession number as PP445034） encoding 319 amino acids. The NalaCLH2 protein had the molecular weight as and the theoretical isoelectric point as 6.75，and it was a stable non-transmembrane non-secretory protein mainly located in chloroplasts.NalaCLH2 was a hydrophilic protein containing chlorophyllase2 conservative domain but without signal peptide and transmembrane structure.Tissue-specific expresion analysis showed that NalaCLH2 gene was expressed in the roots （taproots and lateral roots），stems （upper，middle and lower stems），leaves （upper and lower leaves）and flowers （calyces and petals）of Nicotiana alata，but its expression level was the highest in calyx and the lowest in petal.NalaCLH2 gene was upregulated by low temperature，abscisic acid （ABA），gibberellic acid （GA） and methyl jasmonate （MeJA）induction，while NaCl，drought and brassinolide（BR） inhibited its expression.These results of this study could provide a basis for further analysis of the function of NalaCLH2 gene in abiotic stresses and hormone signal transduction pathway of Nicotiana alata.

KeywordsNicotiana alata; Chlorophyllase2; Gene cloning； Expression pattern analysis

花烟草（NicotianaalataLinketOtto）为茄科（Solanaceae）烟草属（NicotianaL.）有限的多年生草本植物之一，原产阿根廷和巴西[1]，其形态和花型与其他烟草属植物有较大差异，染色体数目少（ 2n=18 ），是组织培养和体细胞杂交的有用材料[2-4]。（剩余14005字）