Importin-?1 Mediates The Nuclear Transport Of EIN2 And The Defense Against Aphid In Arabidopsis

Ethylene gas is necessary for many developmental and stress reactions in plants.Ethylene signaling pathway plays an important role in resisting pathogen and pest infestation.In the model plant Arabidopsis,the most upstream of this pathway are the five receptors ETR1,ETR2,ERS1,ERS2 and EIN4 of ethylene encoded by a multi-gene family.In the absence of ethylene,the binding of the receptor and CTR1 can co-inhibit the downstream ethylene signal.Downstream of the negative control factor is the positive regulator EIN2 of the ethylene signal.EIN2 is a class of large transmembrane proteins located on the endoplasmic reticulum.The N-terminus of EIN2 is structurally similar to the metal ion channel protein;the C-terminal(CEND)has a nuclear localization domain,but the C-terminus of EIN2 has a low homology with the known protein and is presumably functional.Whereas the expression of EIN2CEND at the end of Arabidopsis plants alone can cause responses to downstream of ethylene.EIN2 is the central component of the ethylene signal pathway and is important in plant growth and development and defense response.When plants are subjected to external biological and abiotic stress,EIN2 can participate in different regulatory processes to achieve the role of stress against stress.But the it's nuclear input carrier is still unknown.The Importin-? family is a widely distributed nuclear translocated receptor protein in a class of eukaryotes that is responsible for the transport of most proteins and RNA across cells.Most members of the Importin-? family can directly identify the subcellular localization signal of the substrate,or use a linker protein to identify and bind to a specific substrate.EIN2 protein is very important,but its nuclear input carrier has not been found.The aim of this study was to determine the nuclear input vector for EIN2.Which for the future study of EIN2 has a very important significance.At the same time,it is important to study the key mechanism and molecular mechanism of the import of the intramuscular vector Importin?-1 in the phloem defense reaction and to the wheat pattern.1.Importin-?1 mediates the nuclear transport of EIN2In this study,according to the previous screening of Arabidopsis thaliana and other aspects,suggesting that EIN2 nuclear input vector may be Importin-?1,through yeast two-hybrid,subcellular localization experiments,BiFC experiments were studied.The results showed that Importin-?1 could interact with EIN2 CEND,and the content of EIN2 in the nucleus was significantly increased under the condition of the import of the nuclear input vector,Importin-?1.2.Importin-?1 regulats the phloem defense reactionIn this experiment,the feeding preference and reproduction rate of Myzus persicae(Sulzer)colonized on wild-type Arabidopsis plant and Importin-?1 mutant CS817444 were statistically analyzed.The results showed that the aphidson the mutant plants food preference and reproduction rate have improved.EPG waveform analysis showed that the time and frequency of feeding of aphids in the phloem was increased in the mutant plants.Under the inverted microscope,it was found that the decrease of callose deposition in the leaves of the mutant plants reduced the obstruction of the plantation of the Myzus persicae.The expression levels of PP2-A1,PP2-A2 and GSL2,GSL10 and GSL12 in the mutant plants were detected.The expression of PP2-A1 PP2-A2and GSL2,GSL10 and GSL12 were detected in the phloem decreased,indicating that Importin-?1 was involved in the control of the resistance to aphid in the phloem of Arabidopsis thaliana,the EIN2 gene and the ethylene signaling pathway play an important role in insect resistance.In order to verify whether the insect resistance of the EIN2 gene and the ethylene signaling pathway is applicable in the wheat pattern.The expression of EIN2 gene in silenced wheat was affected by the use of ethylene inhibitors on plants silencing TaMYB19,TaMYB29 and TaMYB44,respectively.The expression of Hfr-1 and Wci-1 and GSL2,GSL10,GSL12 were significantly decreased in phloem The It is further explained that TaMYB19,TaMYB29 and TaMYB44 interact with the ethylene signal pathway to control the phloem defense reaction of wheat and finally achieve the purpose of anti-aphid.