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Effects Mechanism Of Respiratory Metabolism On Taproot Growth In Sugar Beet (Beta Vulgaris L.)

Posted on:2022-06-06Degree:DoctorType:Dissertation
Country:ChinaCandidate:C YuFull Text:PDF
GTID:1483306527989999Subject:Botany
Abstract/Summary:PDF Full Text Request
Sugar beet(Beta vulgaris L.)is a raw material crop for sugar production,and also an important characteristic cash crop in Inner Mongolia.Although beet yield has increased in recent years,there is still a big gap compared with European and American countries;In addition,the yield of home-bred varieties is also lower than that of imported varieties.How to improve the yield of sugar beet is the fundamental concern in the development of beet sugar industry.The plant respiration is closely related to crop growth and development,because it can provide raw materials for the synthesis of protein,fat and polysaccharide,but energy for plant growth as well.In this study,4 different genotypes of sugar beet varieties were used as research materials.The development characteristics of taproot,respiration rate,energy levels,gene expression and enzyme activity of respiration key enzymes at different growth stages were compared with comparative physiology and molecular biology techniques,aimed to clarify the role and physiological mechanism of respiration metabolism in root development of sugar beet,thus provided a theoretical basis for high yield sugar beet production.The main results are abstracted as follows:1.There were differences in root development characteristics among different genotypes of sugar beet.Compared with high sugar content varieties,the high yield varieties showed significantly higher taproot weight and volume and lower sugar content during foliage quick growing stage,root and sucrose increasing stage and sucrose accumulation stages.The higher yield character of high-yield varieties were caused by the faster growth of taproot in early growth stage,but the high sugar content varieties growth slowly at the corresponding period,which could cause higher sugar content.2.The respiration rate,ATP content and energy charge were positively correlated with taproot weight,indicated that the respiratory metabolism can promote the taproot growth of sugar beet.3.There were significant differences in the activities of respiratory metabolic enzymes and gene expression level between different genotypes.The activities of ATPase,IDH and G6 PDH were positively correlated with taproot weight.Experimental results of enzymes activities,gene expression level and verification experiment of respiratory pathway inhibitor showed that TCA cycle contributed the most part in the growth and development of root tuber.4.Bio-informatics analysis of sugar beet genomic data showed that there were 8gene members in sugar beet IDHs gene family belonged to two subgroups.The expression pattern of ICDH gene of taproot in different growth stage showed that the gene family had the highest expression level in foliage quick growing stage and root and sucrose increasing stage,which were 89 % and 84 % of the total expression level respectively.The verification experiment of environment factor(water,temperature and nitrogen)treatment showed that the expression level of ICDH2 was consistent with respiratory rate,root diameter and root weight,indicating that ICDH2 is an important gene regulating taproot expansion by enhancing respiration.
Keywords/Search Tags:Sugar beet, Respiratory rate, Respiratory enzyme, Energy charge, ICDH gene, Physiological mechanism
PDF Full Text Request
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