Sex-related Physiological Responses And Molecular Mechanisms Of Salix Paraplesia To Warming

Dioecious plant is an important part of the terrestrial ecosystem,which plays a positive role in maintaining the structural and functional stability of the terrestrial ecosystem.Sex-related differences present in dioecious plants responsed to stress was related to different reproductive effort between females and males.Climate change,particularly increased temperature is a key factor affecting the growth and development of plants.With global warming,sex-related responses to elevated temperature were detected in dioecious plants in morphology and physiological characteristics.It is difficult to find common conclusions on the sex-related response pattern of dioecious plant to global warming in the literature.Moreover there are few in-depth studies on the interpretation of individual morphological and physiological characteristics at the molecular level.Salix is a common dioecy,which is widely distributed in the world.Their characters of fast-growing,adaptable and easy to cultivate make them play an important role in maintaining ecological stability and forest restoration and often regcongnized as a pioneer species in ecological restoration area.Under the warming conditions,the effect of climate change on the Salix in morphology,physiology and biochemistry is what? Do female and male willow trees have sex-related differential responses to global warming? And how about the molecular mechanism involved in it? In order to explore the answers to above questions,we conduceted a controlled growth chamber experiments(+ 4°C)by using Salix paraplesia cuttings,which is widely distributed shrub in Northwest,Central,and Southwestern China.The experiment was carried out by using the method of artificial climate chamber simulation to explore the morphological,physiological response(including plant height,basal diameter,biomass,gas exchange,peroxidase,proline and cell ultrastructure and so on)and molecular mechanism(including transcriptome and proteome)of the leaves and roots in S.paraplesia.The main results and conclusions are as follows:(1)Physiological response of S.paraplesia leaves and roots to elevated temperatureElevated temperature promoted the plant height,basal diameter,aboveground biomass and total biomass of roots,stems and leafs in S.paraplesia males and females.And also,elevated temperature increased the photosynthetic rate,intercellular carbon dioxide concentration,transpiration rate and chlorophyll concentration,together with S.paraplesia females had faster growth and higher biomass and photosynthetic rate than males.These results showed that the resource acquisition ability of S.paraplesia females was better than that of males.Compared with the control,elevated temperature reduced the starch,total soluble sugar and non-structural carbohydrate content in all tissues of S.paraplesia,and S.paraplesia females showed higher non-structural carbohydrate content and proline content than males.We speculated that S.paraplesia females might be more efficient in resource acquitance than males due to the nutrient absorption of plant root was a process of energy consumption,while S.paraplesia females accumulate more carbohydrate for reproductive growth than males.(2)Transcriptionomic study on S.paraplesia leaves and roots under elevated temperatureThe transcriptional results of S.paraplesia leaves and roots under elevated temperature were carried out by using Illumina Hi Seq TM 4000 technology.Results showed that plenty of genes were enriched in secondary metabolism,plant hormone metabolism,amino acid synthesis and degradation,energy metabolism and cell wall and response stress in S.paraplesia leaves and roots under elevated temperature.Moreover,more differential gene expression(DEGs)in roots than in leaves.In transcriptional level,tissue-specific different responses of S.paraplesia to elevated temperature were involved in bellow: in the aspect of the synthesis of plant hormones,in leaf tissues,DEGs were mainly related to the synthesis and degradation of jasmonic acid,while in root tissues DEGs were mainly related to cytokinin process;in the aspect of secondary metabolite synthesis,elevated temperature activates DEGs related to the anthocyanin synthesis and flavonoids and isoflavones and promote the photosynthesis and carbohydrate synthesis of leaves in S.paraplesia,which is manifested in the increase of light reaction related to photosynthesis pathway and enzyme expression related to starch and sucrose synthesis process.In transcriptional level,sex-specific different responses of S.paraplesia to elevated temperature were involved in bellow: in leaf tissues,there are more DEGs related to anthocyanin and flavonol synthesis,aspartic acid and phenylalanine synthesis,jasmonic acid synthesis and heat shock protein(HSPs)synthesis in S.paraplesia males;more DEGs related to the metabolism pathway of ?-linolenic acid in S.paraplesia females.In root tissues,more DEGs were up regulated in the process of ?-linolenic acid metabolism,aspartic acid and phenylalanine synthesis in root of S.paraplesia females,while more DEGs were involved in cytokinin synthesis in S.paraplesia males roots.Therefore,at the transcriptome level,there are more DEGs related to synthesis of secondary metabolites,amino acids,jasmonates(JAs)and HSPs in the leaves of S.paraplesia males,which can protect it against the negative effects of elevated temperature.(3)Proteomic study on S.paraplesia leaves and roots under elevated temperatureThe result of proteomic study of S.paraplesia leaves and roots under elevated temperature were carried out by using i TRAQ technique.Result showed that elevated temperature had a significant effect on the differential proteins expression(DEPs)related to secondary metabolism,energy metabolism,amino acid synthesis and degradation,hormone synthesis and HSPs synthesis in the leaf and root tissues of S.paraplesia.At the level of proteome,the effect of elevated temperature on the roots was more significant than leaves of S.paraplesia,especially in the roots of S.paraplesia males,for that more DEPs were enriched in roots rather than leaves.At poteomic level,tissue-specific different responses of S.paraplesia to elevated temperature were involved in bellow: in the aspect of synthesis of secondary metabolites,elevated temperature promote the synthesis of secondary metabolites in the leaves and roots of S.paraplesia,while the metabolites types in the leaves and roots response to elevated temperature were different: in the leaves,it was related to the synthesis of anthocyanins,but in the roots,it was related to the synthesis of alkaloids;in the aspect of synthesis of amino acids,elevated temperature increased synthesis of amino acids both in leaves and roots of S.paraplesia,and more DEPs were related to roots;in the aspect of hormone synthesis,DEPs were enriched in the changes of the enzymes of abscisic acid(ABA)synthesis that inhibit growth in the leaves,while in the root,it is mainly related to the jasmonate synthesis process that improves heat resistance;in the aspect of HSPs synthesis,differential pattern of sex-related responses to elevated temperature were detected in leaves and roots of S.paraplesia.In addition,at the proteomic level,results showed that there were significant sex-related responses in the leaves and roots of S.paraplesia.For example,in leaf tissues,DEPs related to anthocyanin synthesis were more in S.paraplesia females than that of males;in the aspect of amino acid synthesis and degradation,in leaves of S.paraplesia females DEPs were mainly enriched in reducing leucine degradation,while in S.paraplesia males leaves it was increased;in the aspect of heat stress proteins synthesis,DEPs related to HSPs synthesis was decreased in leaves of S.paraplesia females,while it was increased in leaves of S.paraplesia males.Furthermore,in root tissues,in the aspect of alkaloids synthesis,DEPs enriched in alkaloids synthesis in root of S.paraplesia males,while depleted in females;as to the energy metabolism,more DEPs enriched in sugar synthesis at the same time increasing the energy supply of sucrose degradation to adapt elevated temperature in root of S.paraplesia males,however,S.paraplesia females perfered to the conservative strategy of reducing the amount of synthetic starch and reducing the amount of starch degradation;DEPs was far more abundance of HSPs in root of S.paraplesia females than that of males.Above all,S.paraplesia males root tissues tend to own more DEPs related to alkaloids,amino acids and JAs synthesis to protect themselves to improve heat tolerance.In conclusion,our results showed that the temperature rise can promote the growth of S.paraplesia,and females has more advantages in resource acquisition ability and sugar accumulation than males of S.paraplesia.Therefore,we speculated that S.paraplesia females would grow better than males under the global warming.Results of transcriptome and proteomics showed that the responses to elevated temperature in different tissues were distinct,with that S.paraplesia roots have more DEPs and DEGs expressed than leaves.Differential gender-specific responses in leaves and roots were obvious,especially in the aspect of energy metabolism,amino acid synthesis and degradation,S.paraplesia females and males adopted different strategies to adapt elevated temperature.S.paraplesia males would have more strategies than females to cope with warming for more they have much more proteins and genes expressed involved in synthesis of amino acids,jasmonic acid and more sugar degradation under elevated temperature.