Advances on molecular mechanisms of Rehmannia glutinosa consecutive monoculture problem formation in multi-omics era / 中国中药杂志

Although consecutive monoculture problems have been studied for many years, no effective treatments are currently available. The complexity of systems triggered the formation of consecutive monoculture problems was one major cause. This paper elaborated the physiological and ecological mechanisms of consecutive monoculture problem formation based on the interaction relationship among multiple factors presented in the rhizosphere soil of consecutive monoculture plants. At same time, in this paper the multiple interactions among cultivated medicinal plants, autotoxic allelochemicals and rhizosphere microbial were proposed to be most important causes that derived the formation of consecutive monoculture problem. The paper also highlighted the advantage of 'omics' technologies integrating plant functional genomics and metabolomics as well as microbial macro-omics in understanding the multiple factor interaction under a particular ecological environment. Additionally, taking R. glutinosa as an example, the paper reviewed the molecular mechanism for the formation of R. glutinosa consecutive monoculture problem from the perspective of the accumulation of allelopathic autotoxins, the rhizosphere microecology catastrophe and theresponding of consecutive monoculture plants. Simultaneously, the roles of mutilple 'omics' technologies in comprehending these formation mechanism were described in detail. This paper provides finally a new insight to solve systematically the mechanism of consecutive monoculture problem formation on molecular level.

Cloning and expression analysis of the expansin gene RgEXPA10 in Rehmannia glutinosa / 药学学报

Using cDNA from Rehmannia glutinosa leaf as template, a 972 bp fragment of expansin gene which containing a 762 bp ORF that encoded 253 amino acids, was cloned, named RgEXPA10, which GenBank accession number for this gene is KF011918. A 1 207 bp genomic sequence of RgEXPA10 was amplified by PCR with leaf DNA as template, sequencing analysis revealed that three exons and two introns in RgEXPA10 genomic sequence, and which GenBank accession number is KF011919. Molecular and bioinformatic analyses indicated that RgEXPA10 protein have DPBB_1 and Pollen_allerg_1 domain, also including a 26 aa nuclear localization signal and a 19 aa transmembrane region. Phylogenetic analysis revealed that RgEXPA10 showed the highest homology with AtEXPA8 among the 26 α-expansins in Arabidopsis thaliana. However, the RgEXPA10 indicated the highest homology with the expansin from Solanum lycopersicum among 22 plant species. Expression patterns using qRT-PCR analysis showed that RgEXPA10 mainly expressed in unfolded leaf, followed by the tuberous root at stage of expanding period, and rarely expressed in senescing leaf. And RgEXPA10 showed higher expression level in tuberous root at 60 and 90 days after emergence. The transcription level of RgEXPA10 significantly reduced under all the three stresses including continuous cropping conditions, salinity and waterlogging. This study will lay foundations for molecular function in development and regulation of different stresses for R. glutinosa.

Molecular cloning and expression analysis of an Aux/IAA gene (RgIAA1) from Rehmannia glutinosa / 中国中药杂志

To clone and analyze a member of the Auxin/indole-3-acetic acid (Aux/IAA) gene family, RgIAA1, from Rehmannia glutinosa. The transcriptional EST database of R. glutinosa was used to clone the new Aux/IAA gene by cDNA probe of AtIAA14. Bioinformatics was applied to analyze the sequence characteristics of RgIAA1 protein and construct phylogenetiC trees. Quantitative RT-PCR has been applied to detect the transcription level of RgIAA1 in seven tissues as well as in leaves under three stresses. The results showed that, the cDNA sequence of RgIAA1 contains 903 bp was obtained. The open reading frame (ORF) of RgIAA1 was 681 bp encoding 226 amino acids, which has typical structural domains and characteristic sequence of Aux/IAA family proteins. RgIAA1 showed the highest expression level in unfolded leaf, followed by the stem. And the expression of RglAA1 was quickly decreased with leaf growing up. The transcription level increased under continuous cropping conditions while it reduced both in salinity and waterlogging stresses. RgIAA1, an Aux/IAA gene from R. glutinosa has been obtained for the first time, which can lay the foundation for further studies about its molecular function in development and responses to stress.