Martinez Patricia Corral, Siemons Charlotte, Schon Michael, Vos Marije, Horstman Anneke, de Maagd Ruud, Seguí-Simarro Jose María, Boutilier Kim
Bioscience, Wageningen University & Research, P.O. Box 16, 6700 AA, Wageningen, Netherlands.
Laboratory of Molecular Biology, Wageningen University & Research, P.O. Box 633, Wageningen, Netherlands.
Plant Cell Rep. 2025 Sep 17;44(10):214. doi: 10.1007/s00299-025-03586-8.
Many plant cells can be induced to regenerate in vitro. We show that successful regeneration during microspore-derived embryo culture relies in part on the ability of embryogenic cells to resolve tissue culture-induced ER stress. During Brassica napus microspore embryogenesis, the immature male gametophyte is induced by a heat stress treatment to develop into a haploid embryo. Different multicellular embryogenic structures develop in response to heat stress, each with a different potential to complete embryo development. The underlying factors that determine the ability of these initially embryogenic structures to successfully complete embryo development are not known. We show that all embryogenic structures exhibit elements of endoplasmic reticulum (ER) stress, like ER expansion and protein-filled ER cisternae, but that the ER stress response is amplified in embryogenic structures with a low potential to complete embryo development. ER stress was amplified even further by treating heat-stressed cultures with trichostatin A, a histone deacetylase inhibitor epidrug that promotes embryogenic cell formation. Pharmacological treatment of microspore-derived embryo cultures with small molecule modulators of ER stress provided further evidence for the role of ER stress in microspore embryo development. Our results suggest that (1) the inability of certain embryogenic structures to resolve their ER stress responses restricts their ability to complete embryo development, and (2) histone deacetylation enhances microspore embryogenesis in B. napus, in part through its activity as an abiotic stress inducer.
许多植物细胞能够被诱导在体外再生。我们发现，小孢子衍生胚培养过程中的成功再生部分依赖于胚性细胞解决组织培养诱导的内质网应激的能力。在甘蓝型油菜小孢子胚胎发生过程中，未成熟雄配子体通过热应激处理被诱导发育成单倍体胚。不同的多细胞胚性结构因热应激而发育形成，每个结构完成胚胎发育的潜力不同。决定这些最初胚性结构成功完成胚胎发育能力的潜在因素尚不清楚。我们发现，所有胚性结构都表现出内质网（ER）应激的特征，如内质网扩张和充满蛋白质的内质网池，但内质网应激反应在完成胚胎发育潜力较低的胚性结构中会被放大。用曲古抑菌素A（一种促进胚性细胞形成的组蛋白脱乙酰酶抑制剂类表皮药物）处理热应激培养物，内质网应激会进一步放大。用内质网应激的小分子调节剂对小孢子衍生胚培养物进行药物处理，为内质网应激在小孢子胚胎发育中的作用提供了进一步证据。我们的结果表明：（1）某些胚性结构无法解决其内质网应激反应，限制了它们完成胚胎发育的能力；（2）组蛋白去乙酰化增强了甘蓝型油菜的小孢子胚胎发生，部分是通过其作为非生物应激诱导剂的活性来实现的。
