Ahmad Mohammad Aijaz, Ahmad Samina Jam Nazeer, Shah Adnan Noor, Ahmad Jam Nazeer, Ahmed Shakil, Al-Qahtani Wahidah H, AbdElgawad Hamada, Shah Anis Ali
Institute of Botany, University of the Punjab Lahore, Punjab, Pakistan.
Department of Botany, University of Agriculture Faisalabad, Punjab, Pakistan.
Mol Biol Rep. 2022 Dec;49(12):11359-11369. doi: 10.1007/s11033-022-07743-0. Epub 2022 Aug 2.
The plants of B. rapa (syn. B. campestris) are the most important food crop of Pakistan for the production of cooking oil. Brassica plants infected by phytoplasma exhibit floral abnormalities including phyllody, virescence, hypertrophied sepal and aborted reproductive organs and affected flower developmental genes which reduces the yield manifold.
The expression level of flower developmental genes in healthy and phytoplasma infected brassica were compared by using semi-quantitative reverse transcription polymerase chain reaction and DNA hybridization. In infected brassica, LEAFY (LFY) gene, controlling the development and maintenance of floral organ, and directly involved in controlling the homeotic gene expression was affected, while APETALA2, regulate the production of sepals and petals, were not altered. Whereas the genes WUSCHEL, APETALA3 and AGAMOUS, were significantly down-regulated, that were responsible for the identity of shoot and central meristem, petals and stamens production, and stamens and carpels development, respectively. The GLUB gene, controlling the production of β-1,3-glucanases enzyme, was highly up-regulated. According to DNA hybridization results, AGAMOUS and APETALA3 were restricted to floral organs territories in healthy and phytoplasma infected brassica, indicating that their expression was tissue-specific. These outcomes indicated that flower abnormalities of phytoplasma infected B. rapa are linked with DNA methylation in the expression of homeotic genes regulating flower development.
Azacitidine act as a DNA demethylating reagent. By applying the foliar spray of azacitidine during the flower development, cells of Phytoplasma infected plants exhibits demethylation of DNA when treated with azacitidine chemical that incorporated as analogue of cytosine during the cell division stage. B. rapa showed the up-regulation of gene expression level significantly that restore the normal production of flowers, ultimately increase the oil production throughout the world.
芜菁（syn. 油菜）植物是巴基斯坦用于生产食用油的最重要粮食作物。受植原体感染的芸苔属植物表现出花异常，包括叶变花、绿变、萼片肥大和生殖器官败育，以及影响花发育基因，这会使产量大幅降低。
通过半定量逆转录聚合酶链反应和DNA杂交比较了健康和受植原体感染的芸苔属植物中花发育基因的表达水平。在受感染的芸苔属植物中，控制花器官发育和维持且直接参与控制同源异型基因表达的LEAFY（LFY）基因受到影响，而调节萼片和花瓣产生的APETALA2基因未改变。而分别负责茎尖和中央分生组织特征、花瓣和雄蕊产生以及雄蕊和心皮发育的WUSCHEL、APETALA3和AGAMOUS基因显著下调。控制β-1,3-葡聚糖酶产生的GLUB基因高度上调。根据DNA杂交结果，AGAMOUS和APETALA3在健康和受植原体感染的芸苔属植物中局限于花器官区域，表明它们的表达具有组织特异性。这些结果表明，受植原体感染的芜菁的花异常与调节花发育的同源异型基因表达中的DNA甲基化有关。
阿扎胞苷作为一种DNA去甲基化试剂。在花发育期间通过叶面喷施阿扎胞苷，受植原体感染植物的细胞在用阿扎胞苷化学处理时表现出DNA去甲基化，阿扎胞苷在细胞分裂阶段作为胞嘧啶类似物掺入。芜菁显示基因表达水平显著上调，恢复了花的正常产生，最终增加了全世界的油产量。
