Study On Morphological And Physiological And Transcriptome Sequencing Of Diapause Berry In Vitis Amurensis

Vitis amurensis.Rupr is an open-cultivation wintering wine grape in northern China.It is not only an important cold-resistant and disease resistant breeding resource,but also an important raw material for the wine industry in Northeast China.The existence of green berries will lead to the decrease of grape yield and greatly affect the quality of wine,which is a big problem for grape variety selection workers.In this study,the fruit dynamic development,seed anatomical structure,phloem ultrastructure,sugar content and metabolic enzyme activity,hormone content,and the expression of differential genes in the transcriptome were analyzed in some developmental stages using’Shuangfeng’,a variety with more green berries.The identification of the key period and the screening of the related genes controlling the formation of green berries in Vitis amurensis were studied.It provided theoretical basis for reducing small green berries and breeding of fine grape varieties.1.The pollination mode of flowe had influence on the number of green berry.By tracking and observing the location of medium and small berries,the size of berries can be sorted according to the diameter of pedicle.In the early stage,the berry enlargement that was limited by the thinner pedicle would be limited throughout the growth period.2.Through the dynamic detection of different types of grape berries from 9 DAF to 53 DAF,it was found that the rapid growth period of large berries was 12 DAF to 32 DAF,and the rapid growth period of large seeds was 12 DAF to 25 DAF.The development of berries was that the seeds reached the mature stage first,and then the enlargement of flesh cell and pericarp was accelerated.3.At 12 DAF,browning of medium seeds and vascular bundles was observed.At 18 DAF,the endosperm was seperated and the outer integmentum of small seeds was not well developed.The number of sieve tubes and conduits of large berries were more than that of medium berries and small berries.The ultrastructure of the pulp transport tissue showed that at 18 DAF,the cell wall of large sieve molecules was thickened and formed a synplast isolation state,while the development of medium sieve molecules was delayed,the secondary wall of sieve plate was thickened and the symplectic state of sieve molecules was formed.In the transchromatic phase,black matter appeared in the sieve element and vessel elements,and apoptosis was observed.In conclusion,at 18 DAF,the middle and small endosperm were aborted,the seeds were poorly developed,the reservoir capacity was weak,and the conduction tissue was poorly developed,which resulted in the thinness of the stalk and pedicel,and the obstruction of nutrient transport,which inhibited its normal enlargement.4.The increased activity of soluble acid invertase and cell wall acid invertase in large berries was earlier than the accumulation of sugar in fruits,which might be due to the fact that most of the photosynthates were decomposed into large berries and further decomposed and utilized.18 DAF was the turning point of invertase activities began to rise,at this time,by comparing different fruit berries of hormone levels,we found that the content of GA₃ and ZR in medium and small berry was lower than that in the large berry,ABA content was higher than that of large,medium berries still staied on ear may be due to the IAA content higher than the small grain and large grain,reduce the abscission layer on the sensitivity of the ethylene.5.The transcriptome libraries of normal and diapause berries were constructed.The results showed that the genes BAG6 and WRKY36 related to cell wall and seed cover development might play an important role in the normal development of grape berries.Differential genes in the auxin signaling pathway and abscisic acid signaling pathway were involved in the development of green berry.NRT1.1regulated the polar transport of auxin,and the ARF2 transcription factor recognized the auxin response element.Under the regulation of AGL8 and EMB2766,the auxin signal transduction of green berry and embryo development were regulated.During berry development,the gene expression levels of ABA receptor and regulatory factor increased gradually,while the gene expression levels of negative regulatory factor PP2CA decreased gradually.The expression levels of most genes differentially expressed in ABA signal transduction pathway were significantly higher than those of large berries（ATPP2CA,ABF2,OST1）at the growth stage（18 DAF）of medium berries.These results indicated that these genes were involved in the regulation of ABA signal transduction and might play a role in promoting green berreis to perceive the external signals and premature senescence.