Brassinosteroid (BR) signaling is very important in plant developmental processes. Its various components interact to form a signaling cascade. These components are widely studied in Arabidopsis; however, very little information is available on tomatoes. Brassinosteroid Insensitive 2 (BIN2), the downstream suppressor of BR signaling, plays a critical role in BR signal pathway, while FRIGIDA as a key suppressor of Flowering Locus C with overexpression could cause early flowering; however, how the BR signaling regulates FRIGIDA homologous protein to adjust flowering time is still unknown. This study identified 12 FRIGIDA-LIKE proteins with a conserved FRIGIDA domain in tomatoes. Yeast two-hybrid and BiFC confirmed that SlBIN2 interacts with 4 SlFRLs, which are sub-cellularly localized in the nucleus. Tissue-specific expression of SlFRLs was observed highly in young roots and flowers. Biological results revealed that SlFRLs interact with SlBIN2 to regulate early flowering. Further, the mRNA level of SlBIN2 also increased in SlFRL-overexpressed lines. The relative expression of SlCPD increased upon SlFRL silencing, while SlDWF and SlBIN2 were decreased, both of which are important for BR signaling. Our research firstly provides molecular evidence that BRs regulate tomato flowering through the interaction between SlFRLs and SlBIN2. This study will promote the understanding of the specific pathway essential for floral regulation.

Brassinosteroids (BRs) are well known for their important role in the regulation of plant growth and development. Plants with deficiency in BR signaling show delayed plant development and exhibit late flowering phenotypes. However, the precise mechanisms involved in this process require investigation. In this study, we cloned homologs of BRASSINOSTEROID INSENSITIVE 2 (SlBIN2), the GSK3-like protein kinase in tomato (Solanum lycopersicum). We characterized growth-related processes and phenotypic changes in the transgenic lines and found that SlBIN2s transgenic lines have delayed development and slow growing phenotypes. SlBIN2s work redundantly to negatively regulate BR signaling in tomato. Furthermore, the transcription factor SlBIN2.1-INTERACTING MYB-LIKE 1 (SlBIML1) was identified as a downstream substrate of SlBIN2s that SlBIN2s interact with and phosphorylate to synergistically regulate tomato developmental processes. Specifically, SlBIN2s modulated protein stability of SlBIML1 by phosphorylating multiple amino acid residues, including the sites Thr266 and Thr280. This study reveals a branch of the BR signaling pathway that regulates the vegetative growth phase and delays floral transition in tomato without the feedback affecting BR signaling. This information enriches our understanding of the downstream transduction pathway of BR signaling and provides potential targets for adjusting tomato flowering time.

Performance of Sponge Gourd Cultivars under Organic and Inorganic Fertilizer Regimes

| This research was carried out at Horticulture Research Farm, The University of Agriculture Peshawar, during 2016. The experimental design was Randomized Complete Block Design (RCBD) with two factors, replicated three times. Factor A was gibberellic acid concentrations i.e. 0, 20, 40 and 60 mgL -1 , while factor B was comprised of dipping durations i.e. 0, 6, 12, and 18 hours respectively. Gibberellic acid concentrations and dipping durations had significant effect on the growth and yield of bitter gourd. Gibberellic acid concentration at @ 60 mgL -1 significantly reduced days to emergence and days to first flower, while increased germination percentage, number of fruits plant -1 , fruit length, fruit weight, plant height, yield plot -1 , total yield and survival percentage. In case of dipping durations, seeds dipped for 18 hours significantly reduced days to emergence and days to first flower, while increased germination percentage, number of fruits plant -1 , fruit length, fruit weight, plant height, yield plot -1 and total yield. Interaction was found non-significant for all the studied parameters except days to emergence, germination percentage and survival percentage. Seeds dipped in gibberellic acid at a level of 60 mgL -1 for 18 hours significantly reduced days to emergence, while increased germination percentage and survival percentage. From results it is concluded that seeds dipped for 18 hours in 60 mgL -1 of gibberellic acid concentrations showed best results on growth and yield of bitter gourd under the agro-climatic conditions of Peshawar.