The rhizosheath, a layer of soil particles that adheres firmly to the root surface by a combination of root hairs and mucilage, may improve tolerance to drought stress. Setaria italica(L.) P. Beauv.(foxtail millet), a...The rhizosheath, a layer of soil particles that adheres firmly to the root surface by a combination of root hairs and mucilage, may improve tolerance to drought stress. Setaria italica(L.) P. Beauv.(foxtail millet), a member of the Poaceae family, is an important food and fodder crop in arid regions and forms a larger rhizosheath under drought conditions. Rhizosheath formation under drought conditions has been studied, but the regulation of root hair growth and rhizosheath size in response to soil moisture remains unclear. To address this question, in this study we monitored root hair growth and rhizosheath development in response to a gradual decline in soil moisture. Here, we determined that a soil moisture level of 10%–14%(w/w)stimulated greater rhizosheath production compared to other soil moisture levels. Root hair density and length also increased at this soil moisture level, which was validated by measurement of the expression of root hair-related genes.These findings contribute to our understanding of rhizosheath formation in response to soil water stress.展开更多
The rhizosheath,a layer of soil grains that adheres firmly to roots,is beneficial for plant growth and adaptation to drought environments.Switchgrass is a perennial C4 grass which can form contact rhizosheath under dr...The rhizosheath,a layer of soil grains that adheres firmly to roots,is beneficial for plant growth and adaptation to drought environments.Switchgrass is a perennial C4 grass which can form contact rhizosheath under drought conditions.In this study,we characterized the microbiomes of four different rhizocompartments of two switchgrass ecotypes(Alamo and Kanlow)grown under drought or well-watered conditions via 16S ribosomal RNA amplicon sequencing.These four rhizocompartments,the bulk soil,rhizosheath soil,rhizoplane,and root endosphere,harbored both distinct and overlapping microbial communities.The root compartments(rhizoplane and root endosphere)displayed low-complexity communities dominated by Proteobacteria and Firmicutes.Compared to bulk soil,Cyanobacteria and Bacteroidetes were selectively enriched,while Proteobacteria and Firmicutes were selectively depleted,in rhizosheath soil.Taxa from Proteobacteria or Firmicutes were specifically selected in Alamo or Kanlow rhizosheath soil.Following drought stress,Citrobacter and Acinetobacter were further enriched in rhizosheath soil,suggesting that rhizosheath microbiome assembly is driven by drought stress.Additionally,the ecotype-specific recruitment of rhizosheath microbiome reveals their differences in drought stress responses.Collectively,these results shed light on rhizosheath microbiome recruitment in switchgrass and lay the foundation for the improvement of drought tolerance in switchgrass by regulating the rhizosheath microbiome.展开更多
基金supported by a grant from the National key Research and Development Program of China(2018YFD0200302 and 2017YFD0301502)the Hong Kong Research Grant Council(AoE/M-05/12,CUHK14122415 and 14160516)+2 种基金a Newton Advanced Fellowship(NSFC-RS:317611130073,NA160430)the National Natural Science Foundation of China(31422047,31872169,31771701)the Shenzhen Overseas Talents Innovation&Entrepreneurship Funding Scheme(The Peacock Scheme)
文摘The rhizosheath, a layer of soil particles that adheres firmly to the root surface by a combination of root hairs and mucilage, may improve tolerance to drought stress. Setaria italica(L.) P. Beauv.(foxtail millet), a member of the Poaceae family, is an important food and fodder crop in arid regions and forms a larger rhizosheath under drought conditions. Rhizosheath formation under drought conditions has been studied, but the regulation of root hair growth and rhizosheath size in response to soil moisture remains unclear. To address this question, in this study we monitored root hair growth and rhizosheath development in response to a gradual decline in soil moisture. Here, we determined that a soil moisture level of 10%–14%(w/w)stimulated greater rhizosheath production compared to other soil moisture levels. Root hair density and length also increased at this soil moisture level, which was validated by measurement of the expression of root hair-related genes.These findings contribute to our understanding of rhizosheath formation in response to soil water stress.
基金This work was supported by the Postdoctoral Science Foundation of China(2020M683593)the Chinese Universities Scientific Fund(2452019150)+4 种基金the Natural Science Foundation of Jiangsu Province(SBK2020042924)the Science Technology and Innovation Committee of Shenzhen(GJHZ20190821160401654)the National Natural Science Foundation of China(32061143023)Platform funding for Guangdong Provincial Enterprise Key Laboratory of Seed and Seedling Health Management Technology(2021B1212050011)the Hong Kong Research Grant Council(AoE/M-05/12,AoE/M-403/16,GRF14160516,14177617,12100318).
文摘The rhizosheath,a layer of soil grains that adheres firmly to roots,is beneficial for plant growth and adaptation to drought environments.Switchgrass is a perennial C4 grass which can form contact rhizosheath under drought conditions.In this study,we characterized the microbiomes of four different rhizocompartments of two switchgrass ecotypes(Alamo and Kanlow)grown under drought or well-watered conditions via 16S ribosomal RNA amplicon sequencing.These four rhizocompartments,the bulk soil,rhizosheath soil,rhizoplane,and root endosphere,harbored both distinct and overlapping microbial communities.The root compartments(rhizoplane and root endosphere)displayed low-complexity communities dominated by Proteobacteria and Firmicutes.Compared to bulk soil,Cyanobacteria and Bacteroidetes were selectively enriched,while Proteobacteria and Firmicutes were selectively depleted,in rhizosheath soil.Taxa from Proteobacteria or Firmicutes were specifically selected in Alamo or Kanlow rhizosheath soil.Following drought stress,Citrobacter and Acinetobacter were further enriched in rhizosheath soil,suggesting that rhizosheath microbiome assembly is driven by drought stress.Additionally,the ecotype-specific recruitment of rhizosheath microbiome reveals their differences in drought stress responses.Collectively,these results shed light on rhizosheath microbiome recruitment in switchgrass and lay the foundation for the improvement of drought tolerance in switchgrass by regulating the rhizosheath microbiome.
基金the National Natural Science Foundation of China(31872169,31901428)Fujian Natural Science Foundation(2021J011049)+2 种基金Newton Advanced Fellowship(NSFC-RS:NA160430)Research Project of Fashu Foundation(MFK23012)the Special Foundation for Yong Scientists of Minjiang University(MJY20008)。
