Comparative Transcriptome Analysis Reveals Stem Secondary Growth of Grafted Rosa rugosa ‘Rosea’ Scion and R. multiflora ‘Innermis’ Rootstock

Abstract

Grafted plant is a chimeric organism formed by the connection of scion and rootstock through stems, so stem growth and development become one of the important factors to affect grafted plant state. However, information regarding the molecular responses of stems secondary growth after grafting is limited. A grafted Rosa plant, with R. rugosa ‘Rosea’ as the scion (Rr_scion) grafted onto R. multiflora ‘Innermis’ as the stock (Rm_stock), has been shown to significantly improve stem thickness. To elucidate the molecular mechanisms of stem secondary growth in grafted plant, a genome-wide transcription analysis was performed using an RNA sequence (RNA-seq) method between the scion and rootstock. Comparing ungrafted R. rugosa ‘Rosea’ (Rr) and R. multiflora ‘Innermis’ (Rm) plants, there were much more differentially expressed genes (DEGs) identified in Rr_scion (6887) than Rm_stock (229). Functional annotations revealed that DEGs in Rr_scion are involved in two Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways: the phenylpropanoid biosynthesis metabolism and plant hormone signal transduction, whereas DEGs in Rm_stock were associated with starch and sucrose metabolism pathway. Moreover, different kinds of signal transduction-related DEGs, e.g., receptor-like serine/threonine protein kinases (RLKs), transcription factor (TF), and transporters, were identified and could affect the stem secondary growth of both the scion and rootstock. This work provided new information regarding the underlying molecular mechanism between scion and rootstock after grafting.

The effects of pumpkin rootstock on photosynthesis, fruit mass, and sucrose content of different ploidy watermelon (Citrullus lanatus)

“…6). Previous studies have reported that physiological differences are strongly correlated with gene expression changes in the scion after grafting and some genes of the scion are upregulated or downregulated by rootstocks (Sun et al 2020). In this study, the activities of IAI, SPS, and SuSy decreased in grafted watermelon lines vs. own-root watermelon lines.…”

Roots play a key role in drought-tolerance of poplars as suggested by reciprocal grafting between male and female clones

“…Combined with biomass allocation, one reason might be that plants would allocate relatively more biomass to their underground parts under water deficit conditions, thereby increasing the absorption and utilization of limited resources (Shipley and Meziane, 2002). Another reason might be that the scion also conferred vigor to the rootstock (Sun et al, 2020) and female rootstocks altered the secondary growth (stem thickness) (P < 0.05) rather than the primary growth (stem length) (P > 0.05) (Cookson and Ollat, 2013). It is evident the growth differences between females and males under well-watered conditions are predominantly linked to shoots, as higher plant height and biomass were observed in female seedlings.…”

Transcriptome analysis reveals the effect of grafting on gossypol biosynthesis and gland formation in cotton

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