Physiological And Ecological Characteristics Of Adversity Adaptation Of Shrub Plants In The Western Ordos Desert

Affected by climate change and human activities,our country's desert areas are facing a series of serious ecological problems,such as land desertification,biodiversity reduction and desert ecosystem degradation.Related ecological environmental protection research appears to be particularly important.It is of great significance to protect the ecological environment and restore vegetation in desert areas,that carring out vegetation survey in desert areas and exploring the physiological and molecular mechanisms of desert plants adapting to adversity.In this study,typical desert shrubs distributed in the West Ordos region of Inner Mongolia were used as the research object.The methods of field vegetation survey,physiological and ecological observation and transcriptome sequencing were used to study the physiological and ecological characteristics of desert shrubs and their transcriptional gene regulation mechanism.The main findings are as follows:1.West Ordos desert shrub vegetation composition is relatively simple,with shrubs as the main dominant species,there are many rare and endangered plants.The vegetation composition in West Ordos is relatively simple.The number of plants such as Zygophyllaceae and Leguminosae is relatively high.And communities with a single species as the dominant species are often formed.Due to the relationship between soil,salinity,and plant interaction,different types,the vegetation composition is different.The plant life forms are mainly ground bud plants and high bud plants,and the ecological type is mostly xerophytic shrubs.2.Different desert shrubs have similar adaptation strategies in adapting to extreme environments.The photosynthetic rate is generally low at noon,and non-stomata restrictive regulation is the main factor.The daily trend of transpiration rate is different.The water use efficiency and photosynthetic rate show the same trend.In the extreme environment dominated by drought and high temperature,the diurnal changes of photosynthesis of different desert shrubs mostly show a "bimodal" curve,that is the "photosynthetic lunch break" method is adopted to adapt to the adversity environment,at 11:00-13:00 in the afternoon.At this time,photosynthesis reduction is regulated by non-stomata restriction.In terms of water physiology and ecology,desert shrubs mainly reduce photosynthesis rate at noon and adjust water use efficiency to adapt to arid environment.There are certain differences in their transpiration rate and water use efficiency.3.There are significant differences in the differential gene expression of three desert shrubs in the Zygophyllaceae family and Ammopiptanthus mongolicus at different ages,and their molecular regulatory mechanisms to adapt to environmental changes are significantly different.(1)The differential genes of the three shrubs of the Zygophyllaceae are mostly enriched in cell composition,amino acid synthesis,etc.,indicating that even if they are the Zygophyllaceae plants,there are certain differences in gene regulation in cell composition and amino acid synthesis.In the pathways related to photosynthesis,differential genes are mainly enriched in Photosystem II and Photosystem I.(2)Different developmental stages and different growing seasons of Mongolian Ammopiptanthus mongolicus leaves have different transcriptional levels of differentially expressed genes.In different environments in summer(July)and winter(January),the net photosynthetic rate of the leaves of Ammopiptanthus mongolicus at different developmental stages are affected by the light response and the dark response.The differentially expressed genes in the light response stage are mainly reflected in in Photosystem II and Photosystem I.In summary,this study explored the vegetation characteristics of desert shrubs in the West Ordos region from different levels of vegetation,individual physiology,and molecular levels,as well as their physiological and ecological mechanisms and molecular mechanisms for adapting to arid environments.It can be a valuable source of rare and endangered plants in desert areas,and provides reference basis for protection and ecological restoration of vegetation.