The MYB34, MYB51, and MYB122 transcription factors are known to regulate indolic glucosinolate （IG） biosynthesis in Arabidopsis thaliana. To determine the distinct regulatory potential of MYB34, MYB51, and MYB122, t...The MYB34, MYB51, and MYB122 transcription factors are known to regulate indolic glucosinolate （IG） biosynthesis in Arabidopsis thaliana. To determine the distinct regulatory potential of MYB34, MYB51, and MYB122, the accumulation of IGs in different parts of plants and upon treatment with plant hormones were analyzed in A. thaliana seedlings. It was shown that MYB34, MYB51, and MYB122 act together to control the biosynthesis of 13M in shoots and roots, with MYB34 controlling biosynthesis of IGs mainly in the roots, MYB51 regulating biosynthesis in shoots, and MYB122 having an accessory role in the biosynthesis of IGs. Analysis of glucosinolate levels in seedlings of myb34, myb51, myb122, myb34 myb51 double, and myb34 myb51 myb122 triple knockout mutants grown in the presence of abscisic acid （ABA）, salicylic acid （SA）, jasmonate （JA）, or ethylene （ET） revealed that： （1） MYB51 is the central regulator of IG synthesis upon SA and ET signaling, （2） MYB34 is the key regulator upon ABA and JA signaling, and （3） MYB122 plays only a minor role in JA/ET-induced glucosinolate biosynthesis. The myb34 myb51 myb122 triple mutant is devoid of IGs, indicating that these three MYB factors are indispensable for IG production under standard growth conditions.展开更多
Formation of somatic embryos from non-germline cells is unique to higher plants and can be manipulated in a variety of species. Previous studies revealed that overexpression of several Arabidopsis genes, including WUS...Formation of somatic embryos from non-germline cells is unique to higher plants and can be manipulated in a variety of species. Previous studies revealed that overexpression of several Arabidopsis genes, including WUSCHEL （WUS）/PLANT GROWTH ACTIVATOR6 （PGA6）, BABY BOOM, LEAFY COTYLEDON1 （LEC1）, and LEC2, is able to cause vegetative-to-embryonic transition or the formation of somatic embryos. Here, we report that a gain-offunction mutation in the Arabidopsis PGA37 gene, encoding the MYBI18 transcription factor, induced vegetative-toembryonic transition, the formation of somatic embryos from root explants, and an elevated LEC1 expression level. Double mutant analysis showed that WUS was not required for induction of somatic embryos by PGA37/MYB118. In addition, overexpression of MYBll5, a homolog of PGA37/MYB118, caused a pga37-like phenotype. A myb118 myb115 double mutant did not show apparent developmental abnormalities. Collectively, these results suggest that PGA37/ MYB118 and MYB115 promote vegetative-to-embryonic transition, through a signaling pathway independent of WUS.展开更多
The plasticity of stem cells in response to environmental change is critical for multicellular organisms.Here,we show that MYB3R-like directly activates the key plant stem-cell regulator WUSCHEL(WUS)by recruiting the ...The plasticity of stem cells in response to environmental change is critical for multicellular organisms.Here,we show that MYB3R-like directly activates the key plant stem-cell regulator WUSCHEL(WUS)by recruiting the methyltransferase ROOT INITIATION DEFECTIVE 2(RID2),which functions in m7G methylation of the 5′cap of WUS mRNA to protect it from degradation.Transcriptomic and molecular analyses showed that protein-folding genes are repressed by WUS to maintain precise protein synthesis in stem cells by preventing the reuse of misfolded proteins.Interestingly,we found that upon heat stress,the MYB3R-like/RID2 module is repressed to reduce WUS transcript abundance through decapping of nascent WUS mRNA.This releases the inhibition of protein-folding capacity in stem cells and protects them from heat shock by eliminating misfolded protein aggregation.Taken together,our results reveal a strategic trade-off whereby plants reduce the accuracy of protein synthesis in exchange for the survival of stem cells at high temperatures.展开更多
Tomato(Solanum lycopersicum)fruits are typically red at ripening,with high levels of carotenoids and a low content in flavonoids.Considerable work has been done to enrich the spectrum of their healthbeneficial phytoch...Tomato(Solanum lycopersicum)fruits are typically red at ripening,with high levels of carotenoids and a low content in flavonoids.Considerable work has been done to enrich the spectrum of their healthbeneficial phytochemicals,and interspecific crosses with wild species have successfully led to purple anthocyanin-colored fruits.The Aft(Anthocyanin fruit)tomato accession inherited from Solanum chilense the ability to accumulate anthocyanins in fruit peel through the introgression of loci controlling anthocyanin pigmentation,including four R2R3 MYB transcription factor-encoding genes.Here,we carried out a comparative functional analysis of these transcription factors in wild-type and Aft plants,and tested their ability to take part in the transcriptional complexes that regulate the biosynthetic pathway and their effi-ciency in inducing anthocyanin pigmentation.Significant differences emerged for SlAN2like,both in the expression level and protein functionality,with splicing mutations determining a complete loss of function of the wild-type protein.This transcription factor thus appears to play a key role in the anthocyanin fruit pigmentation.Our data provide new clues to the long-awaited genetic basis of the Aft phenotype and contribute to understand why domesticated tomato fruits display a homogeneous red coloration without the typical purple streaks observed in wild tomato species.展开更多
文摘The MYB34, MYB51, and MYB122 transcription factors are known to regulate indolic glucosinolate （IG） biosynthesis in Arabidopsis thaliana. To determine the distinct regulatory potential of MYB34, MYB51, and MYB122, the accumulation of IGs in different parts of plants and upon treatment with plant hormones were analyzed in A. thaliana seedlings. It was shown that MYB34, MYB51, and MYB122 act together to control the biosynthesis of 13M in shoots and roots, with MYB34 controlling biosynthesis of IGs mainly in the roots, MYB51 regulating biosynthesis in shoots, and MYB122 having an accessory role in the biosynthesis of IGs. Analysis of glucosinolate levels in seedlings of myb34, myb51, myb122, myb34 myb51 double, and myb34 myb51 myb122 triple knockout mutants grown in the presence of abscisic acid （ABA）, salicylic acid （SA）, jasmonate （JA）, or ethylene （ET） revealed that： （1） MYB51 is the central regulator of IG synthesis upon SA and ET signaling, （2） MYB34 is the key regulator upon ABA and JA signaling, and （3） MYB122 plays only a minor role in JA/ET-induced glucosinolate biosynthesis. The myb34 myb51 myb122 triple mutant is devoid of IGs, indicating that these three MYB factors are indispensable for IG production under standard growth conditions.
文摘Formation of somatic embryos from non-germline cells is unique to higher plants and can be manipulated in a variety of species. Previous studies revealed that overexpression of several Arabidopsis genes, including WUSCHEL （WUS）/PLANT GROWTH ACTIVATOR6 （PGA6）, BABY BOOM, LEAFY COTYLEDON1 （LEC1）, and LEC2, is able to cause vegetative-to-embryonic transition or the formation of somatic embryos. Here, we report that a gain-offunction mutation in the Arabidopsis PGA37 gene, encoding the MYBI18 transcription factor, induced vegetative-toembryonic transition, the formation of somatic embryos from root explants, and an elevated LEC1 expression level. Double mutant analysis showed that WUS was not required for induction of somatic embryos by PGA37/MYB118. In addition, overexpression of MYBll5, a homolog of PGA37/MYB118, caused a pga37-like phenotype. A myb118 myb115 double mutant did not show apparent developmental abnormalities. Collectively, these results suggest that PGA37/ MYB118 and MYB115 promote vegetative-to-embryonic transition, through a signaling pathway independent of WUS.
基金National Natural Science Foundation of China(grant nos.32321001 and 32130009 to Z.Z.)University of Science and Technology of China Research Funds of the Double First-Class Initiative(grant no.YD9100002025 to Z.Z.).
文摘The plasticity of stem cells in response to environmental change is critical for multicellular organisms.Here,we show that MYB3R-like directly activates the key plant stem-cell regulator WUSCHEL(WUS)by recruiting the methyltransferase ROOT INITIATION DEFECTIVE 2(RID2),which functions in m7G methylation of the 5′cap of WUS mRNA to protect it from degradation.Transcriptomic and molecular analyses showed that protein-folding genes are repressed by WUS to maintain precise protein synthesis in stem cells by preventing the reuse of misfolded proteins.Interestingly,we found that upon heat stress,the MYB3R-like/RID2 module is repressed to reduce WUS transcript abundance through decapping of nascent WUS mRNA.This releases the inhibition of protein-folding capacity in stem cells and protects them from heat shock by eliminating misfolded protein aggregation.Taken together,our results reveal a strategic trade-off whereby plants reduce the accuracy of protein synthesis in exchange for the survival of stem cells at high temperatures.
文摘Tomato(Solanum lycopersicum)fruits are typically red at ripening,with high levels of carotenoids and a low content in flavonoids.Considerable work has been done to enrich the spectrum of their healthbeneficial phytochemicals,and interspecific crosses with wild species have successfully led to purple anthocyanin-colored fruits.The Aft(Anthocyanin fruit)tomato accession inherited from Solanum chilense the ability to accumulate anthocyanins in fruit peel through the introgression of loci controlling anthocyanin pigmentation,including four R2R3 MYB transcription factor-encoding genes.Here,we carried out a comparative functional analysis of these transcription factors in wild-type and Aft plants,and tested their ability to take part in the transcriptional complexes that regulate the biosynthetic pathway and their effi-ciency in inducing anthocyanin pigmentation.Significant differences emerged for SlAN2like,both in the expression level and protein functionality,with splicing mutations determining a complete loss of function of the wild-type protein.This transcription factor thus appears to play a key role in the anthocyanin fruit pigmentation.Our data provide new clues to the long-awaited genetic basis of the Aft phenotype and contribute to understand why domesticated tomato fruits display a homogeneous red coloration without the typical purple streaks observed in wild tomato species.
