Identification of suitable reference genes for studies of Syringa pinnatifolia Hemsl.

Abstract

Syringa pinnatifolia Hemsl. (Oleaceae) is a species of shrub with a limited distribution in China. Several chemical compounds with pharmacological effects have been isolated from S. pinnatifolia, including new lignans and sesquiterpenes. Studies of gene expression in this species require the identification of suitable reference genes that are stably expressed under different conditions and in different tissues. To identify candidate reference genes, here we used the geNorm, NormFinder, and BestKeeper algorithms to analyze the stability of 12 candidate genes. The geometric mean of the rankings generated with these algorithms was used to obtain a comprehensive ranking. TBP and PP2A were found to be appropriate reference genes for calli treated with different external stimuli, and TIP41 and TBP were found to be appropriate reference genes in differentiated tissues. When calli and differentiated tissues were considered together, TBP and TIP41 were found to be the most reliable reference genes. The selected genes were validated by analysis of HMGR expression in calli and differentiated tissues. This study is the first to screen candidate reference genes in the genus Syringa and could help guide future molecular studies in this genus. Syringa pinnatifolia Hemsl. (Oleaceae) is a species of shrub with a limited distribution in China [1]. Its peeled stems, roots, and twigs, called shanchenxiang in Chinese, are important in traditional Mongolian medicine [2], where they are used to treat palpitations, angina pectoris, myocardial ischemia, and other cardiovascular diseases [3].Researchers exploring the pharmacological properties of S. pinnatifolia have isolated and identified a variety of chemical compounds, including new lignans [4,5] and sesquiterpenes [6][7][8][9], as well as compounds known from other plants [10,11]. A number of these compounds, acquired from different tissues, exhibit pharmacological effects, including antibacterial [6,10], anti-inflammatory [10,12], antioxidant [4,8], antitumor [13], and cardioprotective [10] effects. The main compounds responsible for the pharmacological properties of S. pinnatifolia are the lignans and terpenes, with the sesquiterpenes showing the strongest effects. Accordingly, it may be useful to determine the biological mechanism governing the distribution of these components within the plant.

Metabolome and transcriptome analyses identify the plant immunity systems that facilitate sesquiterpene and lignan biosynthesis in Syringa pinnatifolia Hemsl.

“…It should be clear that the factors influencing the development and metabolism of plants, such as light, temperature, soil, and humidity, affect the expression of HMGR in S. pinnatifolia . Our previous study showed that low temperatures increase HMGR expression in S. pinnatifolia [ 68 ]. In the present study, the interaction of metabolite characteristics and the expression of some typical genes associated with plant immunity suggested that biotic stimulus, including pathogens and bacteria as referred to in a previous study [ 65 ], would be a potential and feasible approach to accelerate the accumulation of sesquiterpenes and lignans in the cultivation of S. pinnatifolia .…”

“…There were four biological repeats in the qRT-PCR, each with three technical repeats. Detailed information on the primers is provided in Supplementary Table S9, and TBP was chosen as the reference gene based on a previous study [ 68 ]. Gene expression was calculated using the 2 −ΔΔCT method [ 85 ].…”

Isolation and identification of endophytic fungi involved in the promotion of sesquiterpene accumulation in Syringa pinnatifolia

“…Stems were collected from both wild and cultivated S. pinnatifolia at Xiazi Gully in Mount Helan Nature Reserve (N38°29′32″, E105°50′2″) and the cultivation base of Alashan Mongolian Hospital in Alashan East Banner of Alashan (N38°58′41″, E105°54′7″), respectively, both located in Inner Mongolia, China. Potted S. pinnatifolia and calli, the latter induced according to the previously proposed method, [16] were cultivated in the phytotron at the National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China.…”

Alashanines A–C, Three Quinone-Terpenoid Alkaloids from Syringa pinnatifolia with Cytotoxic Potential by Activation of ERK

“…This endemic Chinese species is predominantly distributed in the upland of Helan Mountain, which is located between Ningxia and Inner Mongolia . Under the stress of high altitude, low temperature, drought, and other special abiotic factors in this area, S. pinnatifolia has produced compounds that are different from other plants in this genus. − Previous phytochemical studies of S. pinnatifolia have reported the lignans, sesquiterpenoids, iridoid, and volatile oil, , and our group also has discovered a series of sesquiterpenes, including new skeletons of racemates by using 1 H NMR and LC-MS-guided methods. − However, some signals indicating the presence of alkaloids caught our attention when analyzing the LC-MS data. Therefore, under the guidance of LC-MS, three quinone-terpenoid alkaloids were isolated from this species for the first time, namely alashanines A–C ( 1 – 3 ), as shown in Figure .…”