Inspired by the cockroach’s use of a pitch-roll mode traverses through narrow obstacles,we improve the RHex-style robot by adding two sprawl joints to adjust the body posture,and propose a novel pitch-roll approach t...Inspired by the cockroach’s use of a pitch-roll mode traverses through narrow obstacles,we improve the RHex-style robot by adding two sprawl joints to adjust the body posture,and propose a novel pitch-roll approach that enables an RHex-style robot to traverse through two cylindrical obstacles with a spacing of 90 mm,about 54%body width.First,the robot can pitch up against the obstacle on the one side by the cooperation of its rear and middle legs.Then,the robot rotates one side rear leg to kick the ground fast,meanwhile the sprawl joint on the other side rotates inward to make the robot roll and fall forward.Finally,the robot can rotate the legs on the ground to move the body forward until it crosses the obstacles.In this article,both cylinder and rectangular columns are considered as the narrow obstacles for traversing.The experiments are demonstrated by using the proposed approach,and the results show that the robot can smoothly traverse through different narrow spaces.展开更多
Soybean(Glycine max),an exceptionally nutritious crop rich in high-quality proteins and oils,is extensively used in various food products.Aromatic varieties of soybeans are in particular demand.Characterized by its di...Soybean(Glycine max),an exceptionally nutritious crop rich in high-quality proteins and oils,is extensively used in various food products.Aromatic varieties of soybeans are in particular demand.Characterized by its distinctive popcorn-like aroma,2-acetyl-1-pyrroline(2-AP)is an important volatile compound present in soybeans and other plants.The enzyme betaine aldehyde dehydrogenase(BADH)is closely associated with 2-AP production.However,the transcriptional regulatory network that governs BADH gene expression in soybean remains undefined.In this study,we determined that the transcript levels of the BADH gene,GmBADH2,vary significantly across different soybean organs and differ markedly from those of GmBADH1.We showed that GmMYB93 is a transcriptional repressor that directly regulates the expression of GmBADH2 by binding to the CAGTTA elements in its promoter.Furthermore,the silencing of GmMYB93 significantly reduced 2-AP accumulation in soybeans.Our findings shed light on the genetic mechanisms underlying soybean aroma formation and lay a foundation for developing novel aromatic soybean varieties.展开更多
Carotenoid cleavage dioxygenase 4(CCD4)controls the rate-limiting step ofβ-ionone biosynthesis,making it a valuable target for healthcare and pharmaceutical applications.Nicotiana tabacum,a carotenoid-richd crop spec...Carotenoid cleavage dioxygenase 4(CCD4)controls the rate-limiting step ofβ-ionone biosynthesis,making it a valuable target for healthcare and pharmaceutical applications.Nicotiana tabacum,a carotenoid-richd crop species,is a promising source forβ-ionone production.This study aimed to modify CCD4 activity to increaseβ-ionone yield in tobacco.We identified two isoforms of CCD4 in N.tabacum,NtCCD4a and NtCCD4b,with NtCCD4a exhibiting significantly higher expression levels than NtCCD4b.Using solid-phase microextraction gas chromatography-mass spectrometry(SPME-GC–MS),we demonstrated that NtCCD4a effectively catalyzes the cleavage ofβ-carotene to produceβ-ionone.To improve its enzymatic activity,we applied structure-based rational design to reconstruct the active pocket of NtCCD4a,followed by high-throughput screening of mutant variants.Three single base mutants,F181G,F184L,and F337M,in NtCCD4a showed enhancedβ-ionone production compared to the wild-type,with F337M yielding the highest amount.No synergistic effects were observed among the three mutants.Transgenic tobacco plants expressing the F181G,F184L,and F337M mutations had acceleratedβ-carotene cleavage and increasedβ-ionone production relative to the wild-type NtCCD4a.Our results establish a framework for the design of CCD4 in major crop species through genome editing technology.展开更多
基金This work was supported in part by the National Natural Science Foundation of China(No.51605393)China Postdoctoral Science Foundation(No.2018M633398)+1 种基金State Key Laboratory of Robotics and Systems(HIT)(SKLRS-2020-KF-13)Sichuan Science and Technology Program(2020YJ0035).
文摘Inspired by the cockroach’s use of a pitch-roll mode traverses through narrow obstacles,we improve the RHex-style robot by adding two sprawl joints to adjust the body posture,and propose a novel pitch-roll approach that enables an RHex-style robot to traverse through two cylindrical obstacles with a spacing of 90 mm,about 54%body width.First,the robot can pitch up against the obstacle on the one side by the cooperation of its rear and middle legs.Then,the robot rotates one side rear leg to kick the ground fast,meanwhile the sprawl joint on the other side rotates inward to make the robot roll and fall forward.Finally,the robot can rotate the legs on the ground to move the body forward until it crosses the obstacles.In this article,both cylinder and rectangular columns are considered as the narrow obstacles for traversing.The experiments are demonstrated by using the proposed approach,and the results show that the robot can smoothly traverse through different narrow spaces.
基金funded by the High-Level Talents Project of Henan Agricultural University(111-30501301).
文摘Soybean(Glycine max),an exceptionally nutritious crop rich in high-quality proteins and oils,is extensively used in various food products.Aromatic varieties of soybeans are in particular demand.Characterized by its distinctive popcorn-like aroma,2-acetyl-1-pyrroline(2-AP)is an important volatile compound present in soybeans and other plants.The enzyme betaine aldehyde dehydrogenase(BADH)is closely associated with 2-AP production.However,the transcriptional regulatory network that governs BADH gene expression in soybean remains undefined.In this study,we determined that the transcript levels of the BADH gene,GmBADH2,vary significantly across different soybean organs and differ markedly from those of GmBADH1.We showed that GmMYB93 is a transcriptional repressor that directly regulates the expression of GmBADH2 by binding to the CAGTTA elements in its promoter.Furthermore,the silencing of GmMYB93 significantly reduced 2-AP accumulation in soybeans.Our findings shed light on the genetic mechanisms underlying soybean aroma formation and lay a foundation for developing novel aromatic soybean varieties.
基金funded High-Level Talents project of Henan Agricultural University(111-30501301)Project of the National key R&D Program of China(2021YFA0909600)+3 种基金Natural Science Foundation of Henan Province(242300420141)the China Postdoctoral Science Foundation(2020M672308)Cultivation Program for Young Backbone Teachers at Henan University of Technology(DC 11)Science Project 110202101042(JY 19)/2022530000241007,110202102033,110202202038.
文摘Carotenoid cleavage dioxygenase 4(CCD4)controls the rate-limiting step ofβ-ionone biosynthesis,making it a valuable target for healthcare and pharmaceutical applications.Nicotiana tabacum,a carotenoid-richd crop species,is a promising source forβ-ionone production.This study aimed to modify CCD4 activity to increaseβ-ionone yield in tobacco.We identified two isoforms of CCD4 in N.tabacum,NtCCD4a and NtCCD4b,with NtCCD4a exhibiting significantly higher expression levels than NtCCD4b.Using solid-phase microextraction gas chromatography-mass spectrometry(SPME-GC–MS),we demonstrated that NtCCD4a effectively catalyzes the cleavage ofβ-carotene to produceβ-ionone.To improve its enzymatic activity,we applied structure-based rational design to reconstruct the active pocket of NtCCD4a,followed by high-throughput screening of mutant variants.Three single base mutants,F181G,F184L,and F337M,in NtCCD4a showed enhancedβ-ionone production compared to the wild-type,with F337M yielding the highest amount.No synergistic effects were observed among the three mutants.Transgenic tobacco plants expressing the F181G,F184L,and F337M mutations had acceleratedβ-carotene cleavage and increasedβ-ionone production relative to the wild-type NtCCD4a.Our results establish a framework for the design of CCD4 in major crop species through genome editing technology.
