Stable genetic transformation of plants is a low‐efficiency process, and identification of positive transformants usually relies on screening for expression of a co‐transformed marker gene. Often this involves germinating seeds on solid media containing a selection reagent. Germination on solid media requires surface sterilization of seeds and careful aseptic technique to prevent microbial contamination, but surface sterilization techniques are time consuming and can cause seed mortality if not performed carefully. We developed an antimicrobial cocktail that can be added to solid media to inhibit bacterial and fungal growth without impairing germination, allowing us to bypass the surface sterilization step. Adding a combination of terbinafine (1 μM) and timentin (200 mg l−1) to Murashige and Skoog agar delayed the onset of observable microbial growth and did not affect germination of non‐sterile seeds from 10 different wild‐type and mutant Arabidopsis thaliana accessions. We named this antimicrobial solid medium “MSTT agar”. Seedlings sown in non‐sterile conditions could be maintained on MSTT agar for up to a week without observable contamination. This medium was compatible with rapid screening methods for hygromycin B, phosphinothricin (BASTA) and nourseothricin resistance genes, meaning that positive transformants can be identified from non‐sterile seeds in as little as 4 days after stratification, and transferred to soil before the onset of visible microbial contamination. By using MSTT agar we were able to select genetic transformants on solid media without seed surface sterilization, eliminating a tedious and time‐consuming step.

中文翻译：

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用于筛选非无菌拟南芥种子的抗菌固体培养基

植物的稳定遗传转化是一个低效率的过程，阳性转化体的鉴定通常依赖于筛选共转化标记基因的表达。这通常涉及在含有选择试剂的固体培养基上发芽种子。在固体培养基上发芽需要对种子进行表面灭菌和仔细的无菌技术以防止微生物污染，但表面灭菌技术非常耗时，如果不小心执行，可能会导致种子死亡。我们开发了一种抗菌混合物，可以添加到固体培养基中以抑制细菌和真菌的生长而不影响发芽，使我们能够绕过表面灭菌步骤。在 Murashige 和 Skoog 琼脂中加入特比萘芬 (1 μM) 和特美汀 (200 mg l-1) 的组合延迟了可观察到的微生物生长的开始，并且不影响来自 10 种不同野生型和突变体拟南芥的非无菌种子的萌发加入。我们将这种抗菌固体培养基命名为“MSTT 琼脂”。在非无菌条件下播种的幼苗可以在 MSTT 琼脂上保持长达一周而不会观察到污染。该培养基与潮霉素 B、膦丝菌素 (BASTA) 和诺尔丝菌素抗性基因的快速筛选方法兼容，这意味着在分层后的短短 4 天内即可从非不育种子中鉴定出阳性转化体，并在发病前转移到土壤中。可见的微生物污染。