Humic Acid and Auxins Induced Metabolic Changes and Differential Gene Expression during Adventitious Root Development in Azalea Microshoots
Humic Acid and Auxins Induced Metabolic Changes and Differential Gene Expression during Adventitious Root Development in Azalea Microshoots
复制标题
腐植酸和生长素在杜鹃花微芽不定根发育过程中诱导代谢变化和差异基因表达
DOI：
10.21273/hortsci14885-20
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发表时间：
2020-06-01
期刊：
影响因子：
1.9
通讯作者：
Xia, Yiping
中科院分区：
文献类型：
--
作者：
Elmongy, Mohamed S.;Wang, Xiuyun;Xia, Yiping
本实验研究了胡敏素和胡敏酸在杜鹃试管苗不定根诱导中的作用。为了揭示生长素和HA在这一过程中的调节机制，活性氧（ROS），碳水化合物，酚类化合物和基因表达水平的测量在体外根发育过程中进行。在不定根诱导过程中，与未处理的芽相比，生长素和HA处理的芽中的ROS水平增加，特别是在转移到培养基后的最早时期。添加NAA的培养基在培养7天和14天后，H_2O_2含量分别增加了480%和250%。酚类化合物的水平也增加了在芽处理与生长素和HA，反映了不同的生根促进能力的生长素和HA。在NAA培养基中，21 d后总酚含量最高[68.6 mg·g-1鲜重（FW）]，多酚酸含量最高[121.72 μg咖啡酸/g FW]，总黄酮醇含量最高[162.42 μg槲皮素/g FW]，但在IBA培养基中，21 d后花青素含量最高[49.76 μg花青素/g FW]。可溶性碳水化合物，淀粉和可溶性蛋白质水平的增加，在与所有处理的芽处理，但是，NAA处理的影响是强于其他处理的大多数研究参数。与未处理的微芽相比，NAA显着提高了30%，37%和25%的可溶性碳水化合物，分别在14，21和28天。POD 1基因的表达增加提交到HA处理培养基的芽。生长素反应因子（ARF）的表达水平增加IBA和NAA处理的外植体，表明ARF可能有不同的调节作用，不定根诱导在万年青杜鹃。此外，IAA 1，IAA 9，IAA 14和IAA 27转录本的配置文件进行了分析，以揭示其在万年青杜鹃微芽不定生根的作用。这些结果表明，生长素和HA促进不定根诱导杜鹃植物通过其影响ROS，碳水化合物含量，酚类化合物水平，和表达水平的不同基因的根发育在万年青杜鹃植物。
Auxins and humic acid (HA) were investigated for their roles in adventitious root induction in azalea microshoots in our previous study. To reveal the regulatory mechanisms of auxins and HA in this process, measurements of the levels of reactive oxygen species (ROS), carbohydrates, and phenolic compounds and gene expression during in vitro root development were performed. During the adventitious root induction process, ROS levels in shoots treated with auxins and HA increased compared to untreated shoots, especially during the earliest period after transfer to the media. Media supplemented with NAA experienced increases in H2O2 contents by 480%and 250%, respectively, after 7 and 14 days of culture. The phenolic compound levels were also enhanced in the shoots treated with auxins and HA, reflecting the different rooting-promoting abilities of both auxins and HA. The highest levels of total phenolic [68.6 mg·g−1 fresh weight (FW)], polyphenolic acids (121.72 μg caffic acid/g FW), and total flavonols (162.42 μg quercetin/g FW) were recorded after 21 days for NAA media, but the maximum levels of anthocyanins (49.76 μg cyanindin/g FW) were recorded after 21 days for IBA medium. Soluble carbohydrate, starch, and soluble protein levels were increased in the shoots treated with all treatments; however, the influence of NAA treatments was stronger than that of other treatments for most investigated parameters. The NAA significantly enhanced soluble carbohydrates by 30%, 37%, and 25%, respectively, at 14, 21, and 28 days compared with untreated microshoots. Expression of the POD1 gene increased in the shoots submitted to HA treatment media. Expression levels of auxin response factors (ARFs) increased with IBA- and NAA-treated explants, suggesting that ARFs may have diverse regulatory roles in adventitious root induction in evergreen azalea. Moreover, the profiles of the IAA1, IAA9, IAA14, and IAA27 transcripts were analyzed to reveal their roles in the adventitious rooting of evergreen azalea microshoots. These results indicate that auxins and HA promote adventitious root induction in Rhododendron plants through their impact on ROS, carbohydrate contents, phenolic compound levels, and expression levels of different genes related to root development in evergreen azalea plants.