Limits...
Breeding response of transcript profiling in developing seeds of Brassica napus.

Hu Y, Wu G, Cao Y, Wu Y, Xiao L, Li X, Lu C - BMC Mol. Biol. (2009)

Bottom Line: Higher KCR2 activity is associated with higher C16:0, C18:0, and C18:2 in both cultivars, lower C22:1 and total fatty acid content in ZY821, and lower 18:1 in ZS9.Selective pressure for zero erucic acid, low glucosinolate, high oleic acid and high oil content, as well as high yield, resulted in higher FAD3, ACCase, FAE1, GKTP, Caleosin, GAPDH, and PEPC expression levels and lower KAS3, beta-CT, BcRK6, P450, FatA, Oleosin, FAD6, FatB, alpha-CT and SUC1 expression levels.It also resulted in altered relationships between these genes during storage accumulation in seed development.

View Article: PubMed Central - HTML - PubMed

Affiliation: Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, No, 2 Xudong 2nd Road, Wuhan, 430062, PR China. huyaping_1981@yahoo.com.cn

ABSTRACT

Background: The upgrading of rapeseed cultivars has resulted in a substantial improvement in yield and quality in China over the past 30 years. With the selective pressure against fatty acid composition and oil content, high erucic acid- and low oil-content cultivars have been replaced by low erucic acid- and high oil-content cultivars. The high erucic acid cultivar Zhongyou 821 and its descendent, low erucic acid cultivar Zhongshuang 9, are representatives of two generations of the most outstanding Chinese rapeseed cultivars (B. napus) developed the past 2 decades. This paper compares the transcriptional profiles of Zhongshuang 9 and Zhongyou 821 for 32 genes that are principally involved in lipid biosynthesis during seed development in order to elucidate how the transcriptional profiles of these genes responded to quality improvement over the past 20 years.

Results: Comparison of the cultivar Zhongyou 821 with its descendent, Zhongshuang 9, shows that the transcriptional levels of seven of the 32 genes were upregulated by 30% to 109%, including FAD3, ACCase, FAE1, GKTP, Caleosin, GAPDH, and PEPC. Of the 32 genes, 10 (KAS3, beta-CT, BcRK6, P450, FatA, Oleosin, FAD6, FatB, alpha-CT and SUC1) were downregulated by at least 20% and most by 50%. The Napin gene alone accounted for over 75% of total transcription from all 32 genes assessed in both cultivars. Most of the genes showed significant correlation with fatty acid accumulation, but the correlation in ZS9 was significantly different from that in ZY821. Higher KCR2 activity is associated with higher C16:0, C18:0, and C18:2 in both cultivars, lower C22:1 and total fatty acid content in ZY821, and lower 18:1 in ZS9.

Conclusion: This paper illustrates the response of the transcription levels of 32 genes to breeding in developing rapeseed seeds. Both cultivars showed similar transcription profiles, with the Napin gene predominantly transcribed. Selective pressure for zero erucic acid, low glucosinolate, high oleic acid and high oil content, as well as high yield, resulted in higher FAD3, ACCase, FAE1, GKTP, Caleosin, GAPDH, and PEPC expression levels and lower KAS3, beta-CT, BcRK6, P450, FatA, Oleosin, FAD6, FatB, alpha-CT and SUC1 expression levels. It also resulted in altered relationships between these genes during storage accumulation in seed development.

Show MeSH

Related in: MedlinePlus

Fatty acid accumulation patterns in seed development. (A) The trend of total fatty acid accumulation in seed development. Fatty acids peaked at different times but the end accumulation was similar. (B-J) The accumulation pattern of fatty acids present in both cultivars. Most share similar accumulation patterns, but C18:1 was quite different between the two cultivars. Values in parentheses indicate the relative composition percentage and values in abscissa indicate the seed development stage. The black curves represent ZY821 and the gray curves represent ZS9. Each data point represents the mean ± SD of three replicates.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2697984&req=5

Figure 1: Fatty acid accumulation patterns in seed development. (A) The trend of total fatty acid accumulation in seed development. Fatty acids peaked at different times but the end accumulation was similar. (B-J) The accumulation pattern of fatty acids present in both cultivars. Most share similar accumulation patterns, but C18:1 was quite different between the two cultivars. Values in parentheses indicate the relative composition percentage and values in abscissa indicate the seed development stage. The black curves represent ZY821 and the gray curves represent ZS9. Each data point represents the mean ± SD of three replicates.

Mentions: In the ZS9 cultivar, the total fatty acid content continued to increase and peaked at about 40 DAP, followed by a gentle drop with seed maturation (Fig. 1A). In contrast, ZY821 showed a similar pattern of accumulation of total fatty acids except that it had higher levels at 30 DAP (Fig. 1A). Nine fatty acids were found in ZY821 (Fig. 1B–J) but only five in ZS9 (Fig. 1B–F). Among the five common fatty acids, only oleic acid (C18:1) showed different accumulation patterns (Fig. 1D), whereas the other fatty acids accumulated in similar patterns in both cultivars (Fig. 1B–F). In ZS9, the oleic acid content increased continuously and became a major component at the end (Fig. 1D), whereas in ZY821, oleic acid ascended in the early stages (10–25 DAP) but decreased from 25 DAP to 35 DAP and then remained constant until the end (Fig. 1D). The initial content of all saturated fatty acids (C16:0, C18:0, C20:0 and C22:0) was relatively high but decreased from 15 DAP and reached a minimum at about 25–30 DAP, ultimately comprising a minor proportion of the fatty acids in mature seeds (Fig. 1B, C, G, I). The content of C18:2 was as high as 35–42% during the initial stages (10–15 DAP) and decreased continuously to a final content of about 20% (Fig. 1E). The C18:3 content fluctuated from 6% to 11.4% and was fixed at about 7% in mature seeds (Fig. 1F).


Breeding response of transcript profiling in developing seeds of Brassica napus.

Hu Y, Wu G, Cao Y, Wu Y, Xiao L, Li X, Lu C - BMC Mol. Biol. (2009)

Fatty acid accumulation patterns in seed development. (A) The trend of total fatty acid accumulation in seed development. Fatty acids peaked at different times but the end accumulation was similar. (B-J) The accumulation pattern of fatty acids present in both cultivars. Most share similar accumulation patterns, but C18:1 was quite different between the two cultivars. Values in parentheses indicate the relative composition percentage and values in abscissa indicate the seed development stage. The black curves represent ZY821 and the gray curves represent ZS9. Each data point represents the mean ± SD of three replicates.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2697984&req=5

Figure 1: Fatty acid accumulation patterns in seed development. (A) The trend of total fatty acid accumulation in seed development. Fatty acids peaked at different times but the end accumulation was similar. (B-J) The accumulation pattern of fatty acids present in both cultivars. Most share similar accumulation patterns, but C18:1 was quite different between the two cultivars. Values in parentheses indicate the relative composition percentage and values in abscissa indicate the seed development stage. The black curves represent ZY821 and the gray curves represent ZS9. Each data point represents the mean ± SD of three replicates.
Mentions: In the ZS9 cultivar, the total fatty acid content continued to increase and peaked at about 40 DAP, followed by a gentle drop with seed maturation (Fig. 1A). In contrast, ZY821 showed a similar pattern of accumulation of total fatty acids except that it had higher levels at 30 DAP (Fig. 1A). Nine fatty acids were found in ZY821 (Fig. 1B–J) but only five in ZS9 (Fig. 1B–F). Among the five common fatty acids, only oleic acid (C18:1) showed different accumulation patterns (Fig. 1D), whereas the other fatty acids accumulated in similar patterns in both cultivars (Fig. 1B–F). In ZS9, the oleic acid content increased continuously and became a major component at the end (Fig. 1D), whereas in ZY821, oleic acid ascended in the early stages (10–25 DAP) but decreased from 25 DAP to 35 DAP and then remained constant until the end (Fig. 1D). The initial content of all saturated fatty acids (C16:0, C18:0, C20:0 and C22:0) was relatively high but decreased from 15 DAP and reached a minimum at about 25–30 DAP, ultimately comprising a minor proportion of the fatty acids in mature seeds (Fig. 1B, C, G, I). The content of C18:2 was as high as 35–42% during the initial stages (10–15 DAP) and decreased continuously to a final content of about 20% (Fig. 1E). The C18:3 content fluctuated from 6% to 11.4% and was fixed at about 7% in mature seeds (Fig. 1F).

Bottom Line: Higher KCR2 activity is associated with higher C16:0, C18:0, and C18:2 in both cultivars, lower C22:1 and total fatty acid content in ZY821, and lower 18:1 in ZS9.Selective pressure for zero erucic acid, low glucosinolate, high oleic acid and high oil content, as well as high yield, resulted in higher FAD3, ACCase, FAE1, GKTP, Caleosin, GAPDH, and PEPC expression levels and lower KAS3, beta-CT, BcRK6, P450, FatA, Oleosin, FAD6, FatB, alpha-CT and SUC1 expression levels.It also resulted in altered relationships between these genes during storage accumulation in seed development.

View Article: PubMed Central - HTML - PubMed

Affiliation: Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, No, 2 Xudong 2nd Road, Wuhan, 430062, PR China. huyaping_1981@yahoo.com.cn

ABSTRACT

Background: The upgrading of rapeseed cultivars has resulted in a substantial improvement in yield and quality in China over the past 30 years. With the selective pressure against fatty acid composition and oil content, high erucic acid- and low oil-content cultivars have been replaced by low erucic acid- and high oil-content cultivars. The high erucic acid cultivar Zhongyou 821 and its descendent, low erucic acid cultivar Zhongshuang 9, are representatives of two generations of the most outstanding Chinese rapeseed cultivars (B. napus) developed the past 2 decades. This paper compares the transcriptional profiles of Zhongshuang 9 and Zhongyou 821 for 32 genes that are principally involved in lipid biosynthesis during seed development in order to elucidate how the transcriptional profiles of these genes responded to quality improvement over the past 20 years.

Results: Comparison of the cultivar Zhongyou 821 with its descendent, Zhongshuang 9, shows that the transcriptional levels of seven of the 32 genes were upregulated by 30% to 109%, including FAD3, ACCase, FAE1, GKTP, Caleosin, GAPDH, and PEPC. Of the 32 genes, 10 (KAS3, beta-CT, BcRK6, P450, FatA, Oleosin, FAD6, FatB, alpha-CT and SUC1) were downregulated by at least 20% and most by 50%. The Napin gene alone accounted for over 75% of total transcription from all 32 genes assessed in both cultivars. Most of the genes showed significant correlation with fatty acid accumulation, but the correlation in ZS9 was significantly different from that in ZY821. Higher KCR2 activity is associated with higher C16:0, C18:0, and C18:2 in both cultivars, lower C22:1 and total fatty acid content in ZY821, and lower 18:1 in ZS9.

Conclusion: This paper illustrates the response of the transcription levels of 32 genes to breeding in developing rapeseed seeds. Both cultivars showed similar transcription profiles, with the Napin gene predominantly transcribed. Selective pressure for zero erucic acid, low glucosinolate, high oleic acid and high oil content, as well as high yield, resulted in higher FAD3, ACCase, FAE1, GKTP, Caleosin, GAPDH, and PEPC expression levels and lower KAS3, beta-CT, BcRK6, P450, FatA, Oleosin, FAD6, FatB, alpha-CT and SUC1 expression levels. It also resulted in altered relationships between these genes during storage accumulation in seed development.

Show MeSH
Related in: MedlinePlus