山东农业大学发表《Nature》论文，采用我司直链淀粉磁珠钓取MBP标签蛋白

Article  Open Access Published: 25 January 2023

Stigma receptors control intraspecies and interspecies barriers in Brassicaceae

Jiabao Huang, Lin Yang, Liu Yang, Xiaoyu Wu, Xiaoshuang Cui, Lili Zhang, Jiyun Hui, Yumei Zhao, Hongmin Yang, Shangjia Liu, Quanling Xu, Maoxuan Pang, Xinping Guo, Yunyun Cao, Yu Chen, Xinru Ren, Jinzhi Lv, Jianqiang Yu, Junyi Ding, Gang Xu, Nian Wang, Xiaochun Wei, Qinghui Lin, Yuxiang Yuan, …Qiaohong Duan Show authors

Nature (2023) Cite this article

Abstract
Flowering plants have evolved numerous intraspecific and interspecific prezygotic reproductive barriers to prevent production of unfavourable offspring1. Within a species, self-incompatibility (SI) is a widely utilized mechanism that rejects self-pollen2,3 to avoid inbreeding depression. Interspecific barriers restrain breeding between species and often follow the SI × self-compatible (SC) rule, that is, interspecific pollen is unilaterally incompatible (UI) on SI pistils but unilaterally compatible (UC) on SC pistils1,4,5,6. The molecular mechanisms underlying SI, UI, SC and UC and their interconnections in the Brassicaceae remain unclear. Here we demonstrate that the SI pollen determinant S-locus cysteine-rich protein/S-locus protein 11 (SCR/SP11)2,3 or a signal from UI pollen binds to the SI female determinant S-locus receptor kinase (SRK)2,3, recruits FERONIA (FER)7,8,9 and activates FER-mediated reactive oxygen species production in SI stigmas10,11 to reject incompatible pollen. For compatible responses, diverged pollen coat protein B-class12,13,14 from SC and UC pollen differentially trigger nitric oxide, nitrosate FER to suppress reactive oxygen species in SC stigmas to facilitate pollen growth in an intraspecies-preferential manner, maintaining species integrity. Our results show that SRK and FER integrate mechanisms underlying intraspecific and interspecific barriers and offer paths to achieve distant breeding in Brassicaceae crops.

Protein expression and purification

The constructs of GST, MBP and FLAG fusion protein were transformed into Escherichia coli BL21 (DE3) for protein expression. After induction by 0.5 mM IPTG at 37 °C for 4–6 h, the cells were spun down and resuspended in 5 ml PBS (140 mM NaCl, 2 mM KCl, 2 mM KH2PO4 and 10 mM Na2HPO4.7H2O). Sonicated (SCIENTZ) protein was purified by magnetic GSH beads (BEAVER), amylose magnetic beads (PuriMag Pro) or anti-FLAG magnetic beads (BeyoMag), respectively. The eluted protein was separated by SDS–PAGE and detected by the corresponding antibody after western blot.