RESPONSES OF PLANTS TO ENVIRONMENTAL STRESSES: CHILLING, FREEZING, AND HIGH TEMPERATURE STRESSES

By SOPHIA THOMAS

CONTENTS GASOTRANSMITTERS SIGNALING IN PLANTS UNDER ABIOTIC STRESS AN OVERVIEW 1 IN UENCE OF GASOTRANSMITTERS ON THE PHYSIOLOGY OF PLANTS WITH RESPECT TO ABIOTIC STRESS TOLERANCE 17 GASOTRANSMITTERS AND OMICS FOR ABIOTIC STRESS TOLERANCE IN PLANTS 31 ADVANCEMENT IN THE BIOLOGY OF GASOTRANSMITTERS H2S NO AND ETHYLENE 55 HYDROGEN SUL DE AN EVOLVING GASOTRANSMITTER REGULATING SALINITY AND DROUGHT STRESS RESPONSE IN PLANTS 71 ETHYLENE SYNTHESIS AND REDOX HOMEOSTASIS IN PLANTS RECENT ADVANCEMENT 92 NITRIC OXIDE AND CELLULAR REDOX HOMEOSTASIS IN PLANTS 107 THE FUNCTION OF HYDROGEN SUL DE IN PLANT RESPONSES TO SALINITY AND DROUGHT NEW INSIGHTS 140 HYDROGEN PEROXIDE AND ITS ROLE IN ABIOTIC STRESS TOLERANCE IN PLANTS 163 INTERACTION OF ETHYLENE AND H2S IN PLANT STRESS MANAGEMENT 192 GASOTRANSMITTERS SIGNALING IN PLANTS UNDER ABIOTIC STRESS AN OVERVIEW ABSTRACT PLANT SYSTEMS ARE ALLOWED TO FACE MANY STRESSFUL EXPERIENCES THROUGHOUT THEIR LIFE CYCLE AND DURING THIS STRUGGLING TIME PLANT S OWN DEFENCE MACHINERY WORKS TO STABILIZE INTERNAL METABOLIC ACTIVITIES GASOTRANSMITTER MOLECULES VIZ NITRIC OXIDE NO ETHYLENE CARBON MONOXIDE CO HYDROGEN SULPHIDE H2S AND CARBON DIOXIDE CO2 CONSTITUTE A POWERFUL INTERNAL DEFENCE SYSTEM IN PLANTS WHICH ARE ENDOGENOUSLY SYNTHESISED IN PLANT CELLS IN SPECI C CELLULAR COMPARTMENTS FIG 1 DURING BIOTIC OR ABIOTIC STRESS SITUATIONS THESE GASEOUS SIGNALING MOLECULES POSSESS CERTAIN DEFENCE RELATED ACTIVITIES LIKE GOVERNING CELLULAR REDOX HOMEOSTASIS ROS BALANCING BOOSTING UP THE DEFENCE MACHINERY REGULATING GENETIC MODI CATIONS TO ATTAIN STRESS TOLERANCE IN PLANTS IN ADDITION EXOGENOUS APPLICATIONS OF THESE GASO TRANSMITTERS TO PLANTS APPEAR TO AVAIL ADDITIONAL PROTECTION AGAINST STRESSFUL CONDITIONS LIKE SALINITY DROUGHT HIGH TEMPERATURES AND HEAVY METALS MAINLY THROUGH INDUCING ANTIOXIDANT MACHINERY IN ORDER TO COMBAT OXIDATIVE CELLULAR DAMAGE GASOTRANS MITTERS ALSO APPEAR TO BE INVOLVED IN CROSSTALK WITH OTHER SIGNALING MOLECULES AND PLANT HORMONES WHICH CONSTITUTE A COMPLEX STRATEGIC PATHWAY TO UNDERSTAND THESE COMPLEX STRATEGIES OF GASOTRANSMITTERS ARE CHALLENGING IN PLANT RESEARCH 1 INTRODUCTION TO PLANT GASOTRANSMITTERS CHANGING ENVIRONMENT DAY BY DAY COERCE THE PLANTS TO FACE SEVERAL ABIOTIC STRESSES THESE ABIOTIC STRESSES MAY WORSEN THEIR IMPACT ON PLANT GROWTH AND REGULATION TO FACE SEVERAL CHALLENGING ENVIRONMENTAL ISSUES PLANTS HAVE THEIR OWN SUPPORT SYSTEM INBUILT BY SEVERAL GASOTRANSMITTERS SIGNALING MOLECULES AND SEVERAL PLANT HORMONES 1 ETC DINANT AND SUAREZ LOPEZ 2012 AMONG THESE DEFENSIVE SUPPORT SYSTEMS GASO TRANSMITTERS HAVE MORE PROMINENT AND PROMISING POTENTIAL TO COPE UP WITH NEGATIVE IMPACTS INDUCED BY ABIOTIC STRESSES NITRIC OXIDE NO ETHYLENE CARBON MONOXIDE CO HYDROGEN SULPHIDE H2S AND CARBON DIOXIDE CO2 ARE THE WELL KNOWN GASO TRANSMITTERS IN PLANT BODY INDIVIDUALLY THESE GASOTRANSMITTERS PLAY AN IMPORTANT ROLE IN EACH AND EVERY STEP OF PLANT GROWTH AND DEVELOPMENTAL PROCESSES HOWEVER THESE GASOTRANSMITTER MOLECULES SOMETIMES SHOW STRATEGIC CROSSTALK TOGETHER LI ET AL 2015 DA SILVA AND MODOLO 2018 PREVIOUS STUDIES REPORTED THE INVOLVEMENT OF GASO TRANSMITTERS IN VARIOUS POST TRANSLATIONAL MODI CATIONS DURING CHALLENGING ABIOTIC STRESSES BECAUSE OF GASEOUS NATURE OF THESE SIGNALING MOLECULES THEY ARE PRONE TO INTERACT OTHER SECONDARY METABOLITES LIKE CALCIUM IONS CA2 ROS LIKE H2O2 AND O2 OTHER SIGNALING MOLECULES AND PHYTOHORMONES VERMA ET AL 2020 FIG 1 ACCORDINGLY THESE GASOTRANSMITTER MOLECULES ARE LINKED TOGETHER AND THEY SHOW A CROSSTALK AMONG THEM IN PREVIOUS RESEARCHES IT WAS EXPLORED THAT GASOTRANSMITTERS ARE PARTICIPATING IN EACH AND EVERY STEP OF PLANT GROWTH AND DEVELOPMENT AND THEIR SIGNALING STRATEGIES ARE NOT SO LINEAR LI ET AL 2015 VERMA ET AL 2020 BUT TO UNDER STAND THE COMPLEX MULTIDIMENSIONAL STRATEGIES OF GASOTRANSMITTER MOLECULES MORE RESEARCHES ARE REQUIRED THUS THE MAIN OBJECTIVE OF THIS CHAPTER TO COLLECT INFORMA TION ABOUT GASOTRANSMITTERS INTERACTIVE BEHAVIOUR DURING ACQUISITION OF ABIOTIC STRESS TOLERANCE 1 1 NITRIC OXIDE NO AMONG ALL OTHER GASOTRANSMITTERS NITRIC OXIDE IS A HIGHLY POTENTIAL MULTITASKING MOLECULE CLEARLY DEPICTED BY DOMINGOS ET AL 2015 IN THE PRESENT SCENARIO ON GOING RESEARCHES PROVED ITS PROTECTIVE ROLE AT EACH AND EVERY DEVELOPMENTAL STAGE OF THE PLANT VERMA AND PRASAD 2021A ITS PROTECTIVE ROLE IS NOT LIMITED TO HIGHER PLANTS THE LOWER PLANTS ALSO GET BENE TED TO ITS PROTECTIVE STRATEGIES IN THIS QUEUE QIAN ET AL 2009 AND TIWARI ET AL 2019 REPORTED THAT EXOGENOUSLY SUPPLIED NO IN THE FORM OF SNP IS ABLE TO COPE UP THE ORGANISMS CHLORELLA AND ANABAENA PCC 7120 FROM THE DAMAGING EFFECT OF HERBICIDE AND ALUMINIUM METAL TOXICITY RESPEC TIVELY THE NO HAS THE CAPACITY TO INTERACT WITH DIFFERENT OTHER SIGNALING MOLECULES AND ALSO WITH SEVERAL PHYTOHORMONES THAT S WHY INVOLVEMENT OF NO IS FOUND AT EVERY DEVELOPMENTAL STAGES OF PLANTS DELLEDONNE 2005 NO IS ALSO FOUND MODU LATED BY SECONDARY MESSENGERS I E CGMP CYCLIC ADP RIBOSE CADPR AND CA2 IN THE GUARD CELLS OF VICIA FABA IT HAS BEEN REPORTED THAT NO PROMOTED THE LEVELS OF CYTOSOLIC CA2 GARCIA MATA ET AL 2003 NO REGULATES THIS FUNCTION THROUGH CGMP AND CADPR WHICH ACTIVATES INTRACELLULAR CA2 PERMEABLE CHANNELS NO CAN ALSO ELEVATE FREE CYTOSOLIC CA2 FROM TOBACCO CELLS THAT PROCESS HAS BEEN CONSIDERED UNDER CRYPTOGEIN OR HYPEROSMOTIC STRESS RESPONSE LAMOTTE ET AL 2004 VERMA ET AL 2020 RESPONSES OF PLANTS TO ENVIRONMENTAL STRESSES 2 PLANT GASOTRANS MITTERS ETHYLENE FIG 1 MULTIDIMENSIONAL ROLES OF GASOTRANSMITTERS 1 2 ETHYLENE A POTENTIAL GASEOUS PLANT HORMONE ETHYLENE HAS THE ABILITY TO GOVERN DIFFERENT ASPECTS OF PLANT DEVELOPMENTAL PROCESSES BY INTERACTING WITH OTHER POTENTIAL PLANT HORMONES PREVIOUS STUDY OF VANDENBUSSCHE AND STRAETEN 2012 REPORTED THAT ETHYLENE BIOSYN THESIS IS MODULATED DURING BIOTIC STRESS CONDITION AND ALSO DURING SEVERAL REGULATORY PROCESSES IN PLANTS LIKE FRUIT RIPENING OWERING AND SENESCENCE NODULE FORMATION AT THE TIME OF N XATION AND ALSO IN PLASTICITY REGULATION TO OVERCOME WITH THE CHANGING ENVIRONMENTAL CONDITIONS PREVIOUS STUDIES ALSO FOUND THE INVOLVEMENT OF ETHYLENE TO CONTROL PEROXIDASE ACTIVITY IN MANY PLANTS FOR INSTANCE THE EXOGENOUS APPLICATION OF ETHREL WHICH IS AN ETHYLENE RELEASING COMPOUND CONTROLS THE PEROXIDASE ACTIVITY IN PICEA ABIES PLANT INGEMARSSON 1995 VANDENBUSSCHE AND STRAETEN 2012 RESPONSES OF PLANTS TO ENVIRONMENTAL STRESSES 3