Leafy head formation of the progenies of transgenic plants of Chinese cabbage with exogenous auxin genes

AbstractChinese cabbage plants go through seedling and rosette stages before forming their leafy head. Chinese cabbage plants resemble pak-choi plants at their seedling stage, but in their rosette stage the leaves of Chinese cabbage differentiate, as they increase in size with shorter petioles. In order to understand the molecular pathways that play a role in leafy head formation, transcript abundance of young emerging leaves was profiled during development of two Chinese cabbage genotypes and a single pak-choi genotype. The two Chinese cabbages differed in many aspects, among others earliness, leaf size and shape, leaf numbers, and leafy head shape. Genome-wide transcriptome analysis clearly separated the seedling stages of all three genotypes together with the later stages from pak-choi, from the later developmental stages of both Chinese cabbages (rosette, folding, and heading). Weighted correlation network analysis and hierarchical clustering using Euclidean distances resulted in gene clusters with transcript abundance patterns distinguishing the two Chinese cabbages from pak-choi. Three clusters included genes with transcript abundance affected by both genotype and developmental stage, whereas two clusters showed only genotype effects. This included a genotype by developmental stage cluster highly enriched with the MapMan category photosynthesis, with high expression during rosette and folding in Chinese cabbages and low expression in the heading inner leaves that are not exposed to light. The other clusters contained many genes in the MapMan categories Cell, showing again differences between pak-choi and both Chinese cabbages. We discuss how this relates to the differences in leaf blade growth between Chinese cabbage and pak-choi, especially at the rosette stage. Overall, comparison of the transcriptome between leaves of two very different Chinese cabbages with pak-choi during plant development allowed the identification of specific gene categories associated with leafy head formation.

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Conjunctive Analyses of BSA-Seq and BSR-Seq to Reveal the Molecular Pathway of Leafy Head Formation in Chinese Cabbage

Plants ◽

10.3390/plants8120603 ◽

2019 ◽

Vol 8 (12) ◽

pp. 603

Author(s):

Rui Li ◽

Zhongle Hou ◽

Liwei Gao ◽

Dong Xiao ◽

Xilin Hou ◽

...

Keyword(s):

Candidate Genes ◽

Chinese Cabbage ◽

Bulked Segregant Analysis ◽

Rna Seq ◽

Kinase Gene ◽

Head Development ◽

Head Formation ◽

The Common ◽

Leafy Head ◽

Candidate Regions

As the storage organ of Chinese cabbage, the leafy head was harvested as a commercial product due to its edible value. In this study, the bulked segregant analysis (BSA) and bulked segregant RNA-Seq (BSR) were performed with F2 separation progeny to study the molecular mechanism of leafy head formation in Chinese cabbage. BSA-Seq analysis located four candidate regions containing 40 candidate genes, while BSR-Seq analysis revealed eight candidate regions containing 607 candidate genes. The conjunctive analyses of these two methods identified that Casein kinase gene BrCKL8 (Bra035974) is the common candidate gene related with leafy head formation in Chinese cabbage, and it showed high expression levels at the three segments of heading type plant leaves. The differentially expressed genes (DEGs) between two set pairs of cDNA sequencing bulks were divided into two categories: one category was related with five hormone pathways (Auxin, Ethylene, Abscisic acid, Jasmonic acid and Gibberellin), the other category was composed of genes that associate with the calcium signaling pathway. Moreover, a series of upregulated transcriptional factors (TFs) were also identified by the association analysis of BSR-Seq analysis. The leafy head development was regulated by various biological processes and effected by diverse external environment factors, so our research will contribute to the breeding of perfect leaf-heading types of Chinese cabbage.

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Series-Spatial Transcriptome Profiling of Leafy Head Reveals the Key Transition Leaves for Head Formation in Chinese Cabbage

Frontiers in Plant Science ◽

10.3389/fpls.2021.787826 ◽

2022 ◽

Vol 12 ◽

Author(s):

Xinlei Guo ◽

Jianli Liang ◽

Runmao Lin ◽

Lupeng Zhang ◽

Jian Wu ◽

...

Keyword(s):

Genetic Control ◽

Chinese Cabbage ◽

Morphological Differentiation ◽

Sugar Metabolism ◽

Transcriptome Profiling ◽

Complex Signal ◽

Head Formation ◽

Leaf Tissues ◽

Leafy Head ◽

Heading Stage

Chinese cabbage is an important leaf heading vegetable crop. At the heading stage, its leaves across inner to outer show significant morphological differentiation. However, the genetic control of this complex leaf morphological differentiation remains unclear. Here, we reported the transcriptome profiling of Chinese cabbage plant at the heading stage using 24 spatially dissected tissues representing different regions of the inner to outer leaves. Genome-wide transcriptome analysis clearly separated the inner leaf tissues from the outer leaf tissues. In particular, we identified the key transition leaf by the spatial expression analysis of key genes for leaf development and sugar metabolism. We observed that the key transition leaves were the first inwardly curved ones. Surprisingly, most of the heading candidate genes identified by domestication selection analysis obviously showed a corresponding expression transition, supporting that key transition leaves are related to leafy head formation. The key transition leaves were controlled by a complex signal network, including not only internal hormones and protein kinases but also external light and other stimuli. Our findings provide new insights and the rich resource to unravel the genetic control of heading traits.

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Morphological and genetic characterization of the leafy head of Chinese cabbage (Brassica rapa)

10.18174/457901 ◽

2018 ◽

Author(s):

Xiao Xue Sun

Keyword(s):

Brassica Rapa ◽

Chinese Cabbage ◽

Genetic Characterization ◽

Leafy Head

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CHINESE CABBAGE BrMYB34.2 TRANSCRIPTION FACTOR REGULATES INDOLIC GLUCOSINOLATES BIOSYNTHESIS IN Arabidopsis

Acta Scientiarum Polonorum Hortorum Cultus ◽

10.24326/asphc.2020.1.8 ◽

2020 ◽

Vol 19 (1) ◽

pp. 85-95

Author(s):

Ye Zhao ◽

Yongqiang Zhang ◽

Xianfeng Guo ◽

Yan Ma ◽

Peng Zhang ◽

...

Keyword(s):

Transgenic Plants ◽

Chinese Cabbage ◽

Ectopic Expression ◽

Plant Secondary Metabolites ◽

Orthologous Gene ◽

Phenotypic Analysis ◽

Stress Treatment ◽

Real Time Quantitative Pcr ◽

Aliphatic Glucosinolates ◽

Key Genes

Glucosinolates (GS) are a group of sulfur- and nitrogen-rich plant secondary metabolites that originate fromamino acids and exist mainly in plants in the order Brassicales, such as Arabidopsis thaliana (Arabidopsis) and Chinese cabbage (Brassica rapa ssp. pekinensis). To date, several regulatory components responsible for GS biosynthesis have been identified in Arabidopsis. However, the functions of GS biosynthesis regulators in Chinese cabbage have not been clarified. In our current study, a putative ATR1/MYB34 orthologous gene, BrMYB34.2, was isolated from Chinese cabbage leaves. To investigate the function of this gene, we engineered Arabidopsis plants that overexpress BrMYB34.2 ectopically and phenotypic analysis was performed. Moreover, we assayed the accumulation levels of indolic GS (IGS) and aliphatic glucosinolates in transgenic plants and test the expression of key genes of IGS biosynthesis and tryptophan synthesis by Real-time quantitative PCR. And further analysed the resistance of transgenic plants in 5MT stress treatment. The results indicate that ectopic expression of the BrMYB34.2 gene in Arabidopsis was able to up-regulate the accumulation level of IGS due to the increased expression of IGS and Trp biosynthetic genes. Moreover, overexpression of BrMYB34.2 conferred Arabidopsis 5MT resistance. These results suggest that the BrMYB34.2 gene may function as one of the regulators of IGS and Trp biosynthesis in Chinese cabbage.

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