Published online: 4 May 2022
phytocytokines: 植物细胞因子
the secreted peptides SMALL PHYTOCYTOKINES REGULATING DEFENSE AND WATER LOSS (SCREWs)
flg22, a 22-aa peptide that corresponds to the MAMP flagellin
elf18 (an 18-aa peptide from the bacterial elongation factor Tu (EF-Tu)), phytocytokine PLANT ELICITOR PEPTIDE1 (Pep1) and bacterial Pseudomonas syringae pv. tomato (Pst) DC3000
Our data collectively indicate that SCREWs are pathogen-inducible phytocytokines and protect plants from infection
鉴定受病原菌诱导表达的分泌肽
从转录组中筛到3个，序列比对找到第4个
Three closely related genes, AT1G06135, AT2G31345 and AT1G06137, were significantly upregulated at 30 and 60 min after flg22 treatment and were named SCREW1, SCREW2 and SCREW3, respectively
筛受体
NUT属于XI亚家族LRR-RK
we screened receptor kinases with more than 18 LRRs that are induced by flg22 and for which the ligand remains unknown
NUT consists of an extracellular domain of 22 LRRs, a transmembrane domain and a cytoplasmic kinase domain
NUT是精氨酸天冬氨酸激酶，具有自磷酸化活性
The NUT kinase domain is annotated as an arginine–aspartate (RD) kinase
蛋白互作方法：表面等离子体共振技术
Surface plasmon resonance (SPR) assays
BRASSINOSTEROID INSENSITIVE 1-ASSOCIATED RECEPTOR KINASE1 (BAK1) and its related SERKs are co-receptors of multiple LRR-RKs
叶际微生物利用气孔作为入侵植物的入口，在质外体引起水渍环境，并在此定植。作为防御，MAMPs和DAMPs诱发气孔关闭，阻挡病原微生物的入侵。
fls22会诱发气孔关闭 ，SCREWs不诱发气孔关闭
SCREWs不会影响fls22本身的生物活性，但是会抑制“fls22引起的气孔关闭”，但这种抑制在nut 中就没了
所以SCREWs 抑制 ”fls22引起的气孔关闭“ 这一过程是依赖于NUT的。
screw1/2 and nut mutants were more sensitive to ABA treatment than wild-type plants
水分散失时，ABA升高，关闭气孔，减少水分散失
但是SCREWs也抑制了这一过程，并且也是依赖于NUT的。
气孔的孔径是由type 2C protein phosphatases (PP2Cs）关键信号模块调控的，包括ABI1、 ABI2、 SnRK2s、 OST1 (SnRK2.6)
OST1是在ABA和MAMP诱发气孔关闭的关键酶，OST1引起气孔关闭
OST1 (SnRK2.6)调控 S-type 离子通道 SLOW和SLAC1的去极化以及随后的K + 外排，使气孔关闭
SCREWs 引发ABI1 和 ABI2 的 磷酸化，依赖于NUT
ABI1的磷酸化激活，促进了对OST1的去磷酸化，使得下游S型离子通道活性降低，抑制气孔关闭
总结：
病原微生物侵染引发气孔关闭，阻挡后续病原微生物的入侵，但是气孔的关闭同时引发质外体空间更为严重的水渍环境，帮助了病原微生物的定植。SCREW–NUT通路使关闭的气孔重新打开，加快水分散失，扰乱病原微生物的定植，来起到免疫作用。展示了气孔的动态调节过程。
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【记录】
- 文章写得真流畅，可读性高，图文都很漂亮
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endocytosis:NUT定位在质膜上，被SCREW处理之后，NUT在胞质中也有定位
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