Transcriptome Analysis of Low- and High-Sucrose Pear Cultivars Identifies Key Regulators of Sucrose Biosynthesis in Fruits

2020 ◽  
Vol 61 (8) ◽  
pp. 1493-1506
Author(s):  
Jiahong Lü ◽  
Xin Tao ◽  
Gaifang Yao ◽  
Shaoling Zhang ◽  
Huping Zhang

Abstract Sucrose accumulation is one of the important factors that determine fruit enlargement and quality. Evaluation of the sugar profile of 105 pear cultivars revealed low-sucrose and high-sucrose (HS) types of pear fruits. To better understand the molecular mechanisms governing the sucrose content of pear fruits, this study performed transcriptome analysis during fruit development using low-sucrose ‘Korla’ fragrant pear and HS ‘Hosui’ pear, and a coexpression module uniquely associated with the control of high-sucrose accumulation was identified by weighted gene coexpression network analysis. These results suggested that there are seven candidate genes encoding key enzymes (fructokinase, glucose-6-phosphate isomerase, sucrose phosphate synthase and sucrose synthase) involved in sucrose biosynthesis and several transcription factors (TFs) whose expression patterns correlate with those of genes associated with sucrose biosynthesis. This correlation was confirmed by linear regression analysis between predicted gene expression and sucrose content in different pear cultivars during fruit development. This study provides insight into the molecular mechanism underlying differences in sucrose content across pear cultivars and presents candidate structural genes and TFs that could play important roles in regulating carbohydrate partitioning and sucrose accumulation.

2000 ◽  
Vol 27 (1) ◽  
pp. 81 ◽  
Author(s):  
Frederik C. Botha ◽  
Kevin G. Black

Sucrose accumulation rates, sucrose-phosphate synthase (SPS, EC 2.4.1.14) and soluble sucrose synthase (SuSy, EC 2.4.1.13) activities were measured in internodal tissue from a sugarcane (Saccharum species hybrids) variety N19. The sucrose accumulation rate sharply increases between internodes 3 to 11. In the older internodes SPS activity was at least three times higher than the SuSy activity. A highly significant positive correlation was found between SPS activity and sucrose content. In contrast, no significant correlation was observed between SuSy and sucrose content. In agreement, when radiolabelled glucose was fed to internodes with a high sucrose accumulation rate, label was equally distributed in the hexose moieties of sucrose. This clearly indicates that SPS is the major sucrose synthesis activity in the culm of sugarcane. Different kinetic forms of SPS apparently exist in the internodal tissue at different stages of development.


1992 ◽  
Vol 117 (2) ◽  
pp. 274-278 ◽  
Author(s):  
Takaya Moriguchi ◽  
Kazuyuki Abe ◽  
Tetsuro Sanada ◽  
Shohei Yamaki

Soluble sugar content and activities of the sucrose-metabolizing enzymes sucrose synthase (SS) (EC 2.4.1.13), sucrose-phosphate synthase (SPS) (EC 2.4.1.14), and acid invertase (EC 2.4.1.26) were analyzed in the pericarp of fruit from pear cultivars that differed in their potential to accumulate sucrose to identify key enzymes involved in sucrose accumulation in Asian pears. The Japanese pear `Chojuro' [Pyrus pyrifolia (Burro. f.) Nakai] was characterized as a high-sucrose-accumulating type based on the analysis of mature fruit, while the Chinese pear `Yali' (P. bretschneideri Rehd.) was a low-sucrose-accumulating type throughout all developmental stages. The activity of SS and SPS in `Chojuro' increased during maturation concomitant with sucrose accumulation, whereas the activity of these enzymes in `Yali' did not increase during maturation. The activity of SS and SPS in the former were seven and four times, respectively, higher than those in the latter at the mature stage. Further, among 23 pear cultivars, SS activity was closely correlated with sucrose content, while SPS activity was weakly correlated. Soluble acid invertase activity in `Chojuro' and `Yali' decreased with fruit maturation, but the relationships between soluble invertase activity and sucrose content were not significant. The results indicate that SS and SPS are important determinants of sucrose accumulation in Asian pear fruit and that a decrease of soluble acid invertase activity is not absolutely required for sucrose accumulation.


2002 ◽  
Vol 127 (6) ◽  
pp. 938-943 ◽  
Author(s):  
Yosef Burger ◽  
Uzi Saar ◽  
Nurit Katzir ◽  
Harry S. Paris ◽  
Yelena Yeselson ◽  
...  

Fruit sweetness is the major determinant of fruit quality in melons (Cucumis melo L.) and reflects the concentration of the three major soluble sugars, sucrose, glucose, and fructose, present in the fruit flesh. Of these three sugars, sucrose is the prime factor accounting for both the genetic and the environmental variability observed in sugar content of C. melo fruit. Faqqous (subsp. melo var. flexuosus), a cultivar having a low sucrose and total sugar content, was crossed with Noy Yizre'el (subsp. melo var. reticulatus), a cultivar having a high sucrose and total sugar content. F1 plants had a sucrose content averaging slightly higher than that of the low-sucrose parent, indicating that low sucrose content is nearly completely dominant. Segregation in the F2 and backcross progenies indicated that high sucrose accumulation in melon fruit flesh is conferred by a single recessive gene herein designated suc. When the high-sucrose parent was crossed with the moderate-sucrose landrace known as Persia 202 (subsp. melo var. reticulatus), the segregation in the filial and backcross progenies suggested that additional genetic factors affect the amount of sucrose accumulation.


2018 ◽  
Vol 19 (10) ◽  
pp. 2924 ◽  
Author(s):  
Yingbin Xue ◽  
Qingli Zhuang ◽  
Shengnan Zhu ◽  
Bixian Xiao ◽  
Cuiyue Liang ◽  
...  

Phosphorus (P) deficiency is a major limitation for legume crop production. Although overall adaptations of plant roots to P deficiency have been extensively studied, only fragmentary information is available in regard to root nodule responses to P deficiency. In this study, genome wide transcriptome analysis was conducted using RNA-seq analysis in soybean nodules grown under P-sufficient (500 μM KH2PO4) and P-deficient (25 μM KH2PO4) conditions to investigate molecular mechanisms underlying soybean (Glycine max) nodule adaptation to phosphate (Pi) starvation. Phosphorus deficiency significantly decreased soybean nodule growth and nitrogenase activity. Nodule Pi concentrations declined by 49% in response to P deficiency, but this was well below the 87% and 88% decreases observed in shoots and roots, respectively. Nodule transcript profiling revealed that a total of 2055 genes exhibited differential expression patterns between Pi sufficient and deficient conditions. A set of (differentially expressed genes) DEGs appeared to be involved in maintaining Pi homeostasis in soybean nodules, including eight Pi transporters (PTs), eight genes coding proteins containing the SYG1/PHO81/XPR1 domain (SPXs), and 16 purple acid phosphatases (PAPs). The results suggest that a complex transcriptional regulatory network participates in soybean nodule adaption to Pi starvation, most notable a Pi signaling pathway, are involved in maintaining Pi homeostasis in nodules.


2020 ◽  
Author(s):  
Kashif Shahzad ◽  
Xuexian Zhang ◽  
Liping Guo ◽  
Tingxiang Qi ◽  
Huini Tang ◽  
...  

Abstract Background: Heterosis breeding is the most useful method for yield increase around the globe. Heterosis is an intriguing process to develop superior offspring to either parent in the desired character. The biomass vigor produced during seedling emergence stage has a direct influence on yield heterosis in plants. Unfortunately, the genetic basis of early biomass vigor in cotton is poorly understood. Results: Three stable performing F1 hybrids varying in yield heterosis named as high, medium and low hybrids with their inbred parents were used in this study. Phenotypically, these hybrids established noticeable biomass heterosis during the early stage of seedling growth in the field. Transcriptome analysis of root and leaf revealed that hybrids showed many differentially expressed genes (DEGs) relative to their parents, while the comparison of inbred parents showed limited number of DEGs indicating similarity in their genetic constitution. Further analysis indicated expression patterns of most DEGs were overdominant in both tissues of hybrids. According to GO results, functions of overdominance genes in leaf were enriched for chloroplast, membrane, and protein binding, whereas functions of overdominance genes in root were enriched for plasma membrane, extracellular region, and responses to stress. We found several genes of circadian rhythm pathway related to LATE ELONGATED HYPOCOTYL (LHY) showed downregulated overdominant expressions in both tissues of hybrids. In addition to circadian rhythm, several leaf genes related to Aux/IAA regulation, and many root genes involved in peroxidase activity also showed overdominant expressions in hybrids. Twelve genes involved in circadian rhythm plant were selected to perform qRT-PCR analysis to confirm the accuracy of RNA-seq results. Conclusions: Through genome-wide comparative transcriptome analysis, we strongly predict that overdominance at gene expression level plays a pivotal role in early biomass vigor of hybrids. The combinational contribution of circadian rhythm and other metabolic process may control vigorous growth in hybrids. Our result provides an important foundation for dissecting molecular mechanisms of biomass vigor in hybrid cotton.


1969 ◽  
Vol 38 (3) ◽  
pp. 128-131
Author(s):  
M. A. Lugo-López ◽  
B. G. Capó

Data are presented to show the influence of elevation on sucrose yields of four varieties of sugarcane: P.O.J. 2878, B.H. 10(12), P.R. 803, and F.C. 916. An over-all examination of the data from 695 crops harvested during a 10-year period, 1939-49, disclosed that elevations higher than 10 m. above mean sea level favor high sucrose accumulation in sugarcane. This effect was more pronounced with some varieties than with others. This influence of altitude is probably a reflection of climatic effects. Data are presented to show that cane growing at high elevations within a given area, enjoys about the same benefits from sunlight, as measured by "total day-degrees", with the added advantage of cooler nights.


2020 ◽  
Author(s):  
Bingmiao Gao

Abstract Background: Alpinia oxyphylla is an important edible and medicinal herb, and its dried fruits are widely used in traditional herbal medicine. Flavonoids are one of the main chemical compounds in A. oxyphylla ; however, the genetic and molecular mechanisms of flavonoid biosynthesis are not well understood. Methods: We performed transcriptome analysis in the fruit, root, and leaf tissues of A. oxyphylla to delineate tissue-specific gene expression and metabolic pathways in this medicinal plant. Results: In all, 8.85, 10.10, 8.68, 6.89, and 8.51 Gb clean data were obtained for early-, middle-, and late-stage fruits, leaves, and roots, respectively. Furthermore, 50,401 unigenes were grouped into functional categories based on four databases, namely Nr (47,745 unigenes), Uniprot (49,685 unigenes), KOG (20,153 unigenes), and KEGG (27,285 unigenes). A total of 3,110 differentially expressed genes and five distinct clusters with similar expression patterns were obtained, in which 27 unigenes encoded 13 key enzymes (such as CHS, CHI, F3H, FLS, ANS ) associated with flavonoid biosynthesis. Conclusion: The tissue-specific expression of the genes corresponds to accumulation of flavonoids in these tissues.These results provide insights into the molecular mechanism of flavonoid biosynthesis in A. oxyphylla and application of genetically engineered varieties of A. oxyphylla .


Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 693
Author(s):  
Jijun Li ◽  
Sidra Iqbal ◽  
Yuting Zhang ◽  
Yahui Chen ◽  
Zengdong Tan ◽  
...  

Flooding results in significant crop yield losses due to exposure of plants to hypoxic stress. Various studies have reported the effect of flooding stress at seedling establishment or later stages. However, the molecular mechanism prevailing at the germination stage under flooding stress remains enigmatic. The present study highlights the comparative transcriptome analysis in two rapeseed lines, i.e., flooding-tolerant (Santana) and -sensitive (23651) lines under control and 6-h flooding treatments at the germination stage. A total of 1840 up-regulated and 1301 down-regulated genes were shared by both lines in response to flooding. There were 4410 differentially expressed genes (DEGs) with increased expression and 4271 DEGs with reduced expression shared in both control and flooding conditions. Gene ontology (GO) enrichment analysis revealed that “transcription regulation”, “structural constituent of cell wall”, “reactive oxygen species metabolic”, “peroxidase”, oxidoreductase”, and “antioxidant activity” were the common processes in rapeseed flooding response. In addition, the processes such as “hormone-mediated signaling pathway”, “response to organic substance response”, “motor activity”, and “microtubule-based process” are likely to confer rapeseed flooding resistance. Mclust analysis clustered DEGs into nine modules; genes in each module shared similar expression patterns and many of these genes overlapped with the top 20 DEGs in some groups. This work provides a comprehensive insight into gene responses and the regulatory network in rapeseed flooding stress and provides guidelines for probing the underlying molecular mechanisms in flooding resistance.


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