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Flowering transition is one of the most important developmental processes of higher plants, which is controlled by endogenous and external environmental signals. These signaling cues are perceived in leaves and shoot apical meristem (SAM) to induce flower formation. APETALA1 (AP1) is one of floral meristem identity genes that regulate the specification and formation of floral meristems and is required for sepals and petals formation. In this study, the expression of this gene in different organs of Eruca sativa as well as the effect of brassinosteroids (BRs) on flowering and the gene expression was investigated. RNA was extracted from different organs and first-strand cDNA was synthesized. Specific primers were designed based on the sequence alignment of AP1 isoform genes from other plants. In the vegetative stage, no expression was observed in different organs. Brassinosteroid treatment from 28 days (vegetative stage) to flower buds formation caused early flowering, so that the treated plants flower about 10 days earlier than the control. In addition, plant size and its organs were larger in plants treated with brassinosteroids. Evaluation of EvsAP1 gene expression in reproductive phase showed its expression in flower buds, sepals and petals but no was seen in roots, stems, leaves, stamen and gynocium. Also, the onset of expression of this gene was observed earlier, indicating that the transition to flowering and flower bud formation occurs faster in treated plants; therefore, expression occurs earlier. However, expression levels did not affected by brassinosteroids and no significant difference was observed between treated and control samples.
 

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The response of plants to drought stress depends on several factors including the plant developmental stage and the length and severity of the stress applied. Common bean (Phaseolus vulgaris L.) is the most important pulse crop that is cultivated worldwide for human consumption. Understanding of the mechanisms responsible for its response to drought is, therefore, essential. An increasing number of reports show that withdrawal of water from plants growing in the controlled conditions is accompanied by changes in the expression of a number of genes. To our knowledge, regulation of gene expression in flower buds of P. vulgaris under stress conditions has not been reported. Our aim was to identify transcription sensitivity of CA7 and NCED genes under water deficit stress at vegetative and reproductive stages of different bean genotypes. Two experiments were carried out. Within each experiment, the groups of drought-stressed plants were subjected to water withholding, while the control plants were watered every other day. Stressed plants were re-irrigated when RWC reached 66±2 percent. Our study showed that CA7 and NCDE were genes differentially expressed in the studied genotypes under drought stress. The expression of these genes was strongly induced in response to drought stress in flower buds of the cultivar Jules and the line KS-21191. It seems that under stress conditions, these genes express more in the tolerant than the susceptible genotypes. Therefore, these two genes could probably be used to obtain plants relatively tolerant to water deficit stress, especially in the reproductive stage of plant growth.