All genes encoding chloroplast antioxidant enzymes are nuclear-encoded and posttranscriptionally targeted to chloroplasts. The transcript levels of most of them decreased upon sucrose feeding like the transcript level...All genes encoding chloroplast antioxidant enzymes are nuclear-encoded and posttranscriptionally targeted to chloroplasts. The transcript levels of most of them decreased upon sucrose feeding like the transcript levels of many genes encoding components of the photosynthetic electron transport chain. However, the transcript abundance of stromal ascorbate peroxidase （s-APX; At4g08390） increased. Due to mild sugar application conditions, the plants kept the phosphorylation status of the ADP＋ATP pool and the redox states of the NADPH＋NADP~ and the ascorbate pools under control, which excludes them as signals in s-APX regulation. Correlation with ascorbate pool size regulation and comparison of transcript abundance regulation in the starch-biosynthetic mutant adgl, the ascorbate biosynthesis mutant vtcl, and the abscisic acid （ABA） biosynthetic mutant aba2 showed a link between sugar induction of s-APX and ascorbate biosynthesis.展开更多
Bananas(Musa spp.)are one of the world’s most important fruit crops and play a vital role in food security for many developing countries.Most banana cultivars are triploids derived from inter-and intraspecific hybrid...Bananas(Musa spp.)are one of the world’s most important fruit crops and play a vital role in food security for many developing countries.Most banana cultivars are triploids derived from inter-and intraspecific hybrid-izations between the wild diploid ancestor species Musa acuminate(AA)and M.balbisiana(BB).We report two haplotype-resolved genome assemblies of the representative AAB-cultivated types,Plantain and Silk,and precisely characterize ancestral contributions by examining ancestry mosaics across the genome.Widespread asymmetric evolution is observed in their subgenomes,which can be linked to frequent homol-ogous exchange events.We reveal the genetic makeup of triploid banana cultivars and verify that subge-nome B is a rich source of disease resistance genes.Only 58.5%and 59.4%of Plantain and Silk genes,respectively,are present in all three haplotypes,with>50%of genes being differentially expressed alleles in different subgenomes.We observed that the number of upregulated genes in Plantain is significantly higher than that in Silk at one-week post-inoculation with Fusarium wilt tropical race 4(Foc TR4),which con-firms that Plantain can initiate defense responses faster than Silk.Additionally,we compared genomic and transcriptomic differences among the genes related to carotenoid synthesis and starch metabolism between Plantain and Silk.Our study provides resources for better understanding the genomic architecture of culti-vated bananas and has important implications for Musa genetics and breeding.展开更多
文摘All genes encoding chloroplast antioxidant enzymes are nuclear-encoded and posttranscriptionally targeted to chloroplasts. The transcript levels of most of them decreased upon sucrose feeding like the transcript levels of many genes encoding components of the photosynthetic electron transport chain. However, the transcript abundance of stromal ascorbate peroxidase （s-APX; At4g08390） increased. Due to mild sugar application conditions, the plants kept the phosphorylation status of the ADP＋ATP pool and the redox states of the NADPH＋NADP~ and the ascorbate pools under control, which excludes them as signals in s-APX regulation. Correlation with ascorbate pool size regulation and comparison of transcript abundance regulation in the starch-biosynthetic mutant adgl, the ascorbate biosynthesis mutant vtcl, and the abscisic acid （ABA） biosynthetic mutant aba2 showed a link between sugar induction of s-APX and ascorbate biosynthesis.
基金funded by the Strategy of Rural Vitalization of Guangdong Provinces (2022-NPY-00-003,2022-NJS-00-001)the National Natural Science Foundation of China (32270712)+4 种基金the earmarked fund for CARS (CARS-31-01)GDAAS (202102TD,R2020PY-JX002)the Ba-Gui Scholar Program of Guangxi (to Z.-G.H)the Laboratory of Lingnan Modern Agriculture Project (NT2021004)the Maoming Branch Grant (2021TDQD003).
文摘Bananas(Musa spp.)are one of the world’s most important fruit crops and play a vital role in food security for many developing countries.Most banana cultivars are triploids derived from inter-and intraspecific hybrid-izations between the wild diploid ancestor species Musa acuminate(AA)and M.balbisiana(BB).We report two haplotype-resolved genome assemblies of the representative AAB-cultivated types,Plantain and Silk,and precisely characterize ancestral contributions by examining ancestry mosaics across the genome.Widespread asymmetric evolution is observed in their subgenomes,which can be linked to frequent homol-ogous exchange events.We reveal the genetic makeup of triploid banana cultivars and verify that subge-nome B is a rich source of disease resistance genes.Only 58.5%and 59.4%of Plantain and Silk genes,respectively,are present in all three haplotypes,with>50%of genes being differentially expressed alleles in different subgenomes.We observed that the number of upregulated genes in Plantain is significantly higher than that in Silk at one-week post-inoculation with Fusarium wilt tropical race 4(Foc TR4),which con-firms that Plantain can initiate defense responses faster than Silk.Additionally,we compared genomic and transcriptomic differences among the genes related to carotenoid synthesis and starch metabolism between Plantain and Silk.Our study provides resources for better understanding the genomic architecture of culti-vated bananas and has important implications for Musa genetics and breeding.
