| Zantedeschia hybrida due to flower type peculiar and bright color,has an important cut flower plant and very popular in the international flower market.However,the phenomenon of spathe "regreening" will appear after full flowering,which will affect the quality of postharvest and reduce economic benefits.This is the main problem in the flower trade at present.At present,the research on the regreening of spathe is relatively simple,and the related mechanism needs to be clarified.Therefore,it is of great significance for the maintenance of flower market economic system to explore the causes of regreening and find effective ways to solve the regreening problem.In this study,’Florex Gold’,a yellow cultivar of Zantedeschia hybrida,was used as the experimental material to identify the differences in phenotype,pigment content and distribution and plastid structure during the regreening process.The key genes Zh Glu TR and Zh Chl H were identified by transcriptome sequencing.The VIGS system was constructed by selecting sampling spathe site and infection duration.The regreening phenomenon was preliminarily explained and provided theoretical basis and technical support for the subsequent gene function verification.The main research results were as follows:1.In the regreening process of the spathe of Zantedeschia hybrida,according to the development of the outer skin color on the back of the spathe,it can be divided into three stages: full flowering stage(S1),early greening stage(S2)and late greening stage(S3).The results showed that the chlorophyll content increased significantly and the carotenoid content decreased significantly during the regreening process.The main body of photosynthetic pigments distributed in the lower epidermal cells on the back of the spathe changed from yellow carotenoids to green chlorophyll.Ultrastructure showed that the chloroplasts to form the process function,namely in the S3 issue observed close to the chloroplast structure of mature leaves.2.The Hiseq2500 platform was used for transcriptome sequencing of the spathe from the above three periods.The sequencing results obtained about 30.5 G of data.A total of 109,286 unigenes were obtained,with an average length of 611.73 bp.Annotation information accounted for 27.54% of all unigenes.Analysis of differentially expressed genes showed that S1 and S2,which were the key stages of regreening,had a total of 1,802 DEGs,which could be significantly enriched in photosynthetic related pathways.Combined with the existing results of this study,it is concluded that chlorophyll,as a photosynthetic pigment,plays a major regulatory role in regreening.Four genes were randomly selected for q RT-PCR verification,and the results were completely consistent with the transcriptome expression trend.3.The transcriptomes were analyzed to obtain the key genes Zh Glu TR and Zh Chl H in the chlorophyll biosynthesis pathway during the greening process,which were used as indicator genes to construct VIGS system in vitro.The sampling site and infection duration of isolated pores were optimized.The results showed that the experimental group with vacuum pumping for 5 min in the middle showed the latest regreening phenomenon,the chlorophyll content was lower than that of the control group,and the expression of q RT-PCR was significantly decreased.The successful construction of VIGS system has laid the theoretical basis and technical support for the subsequent gene function verification. |
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