Although much information regarding the chloroplast and chromoplast biosynthesis has been accumulated in recent years, details of the physiological, biochemical, and molecular differences between green tissues and colorful chromoplast tissues are still poorly understood. In this study, the pigment accumulation, plastid ultrastructure, and the expression of genes involved in chloroplast synthesis were analyzed between leaf and corolla in cabbage and rapeseed. The results showed that both petals contained less chlorophyll contents and a lower ratio of Chl a/b, but contained higher carotenoid contents compared with that of sepals and leaves. Accordingly, ultrastructural observations indicated that plastid development of petals was arrested or inhibited. In addition, data obtained from biochemical studies were correlated with those at the mRNA level, the transcripts of almost all the chlorophyll biosynthetic genes (especially the downstream genes) and plastid genes required for early chloroplast development and photosynthesis were higher in leaves than that in petals. Besides, the different pigment accumulation in corollas was also corroborated by the changes in the expression of selected genes associated with chlorophyll accumulation and/or chloroplast development. Collectively, the results contribute to better understand the molecular mechanisms underlying tissue-specific chloroplast development in plants.

MADS-box family transcription factors are key regulators of plants and are involved in many biological processes. However, to date little information regarding stress-related MADS-box genes is available in tomato. To further elucidate the function of the SlMBP11 gene in response to abiotic stress, we generated transgenic tomato plants with knockdown SlMBP11 by RNA interference (RNAi) and plants overexpressing SlMBP11, and investigated the effects of salt stress on wild-type (WT), RNAi and overexpressing plants. In our study, seedling growth of SlMBP11-RNAi plants was more inhibited by salt than that of WT at post-germination stage, and RNAi plants became less tolerant to salt stress than WT plants in soil, which was demonstrated by lower relative water and chlorophyll content, and higher relative electrolyte leakage and malondialdehyde (MDA) content. In contrast, overexpressing plants had no obvious difference from WT seedlings when challenged by NaCl at post-germination stage, and overexpression of SlMBP11 in tomato enhanced tolerance to salt stress, which was confirmed by lower relative electrolyte leakage and MDA content, and higher water and chlorophyll content in transgenic plants. In addition, the expression of genes related to chlorophyll biosynthesis, photosystem and stress was changed in opposite directions in SlMBP11-RNAi and overexpressing plants under control and salt-stressed conditions. Together, these results highlighted the important role of SlMBP11 as a stress-responsive transcription factor in the positive modulation of salt-stress tolerance, possibly through an abscisic acid-independent signaling network, and may have promising applications in the engineering of salt-tolerant tomato.

Chrysanthemums (Dendranthema morifolium) are one of the most economically important perennial flowering plants, with floricultural (cut flowers), ornamental crop (pot and garden flowers) and, for some cultivars, medicinal uses. Plant architecture is an important agronomic trait for plants with a high ornamental and economic value. In this study, two miniature-related genes, DmCPD and DmGA20ox, were cloned and their tissue-specific expression patterns were analyzed. The results showed that the two genes were both highly expressed in stems, mature leaves, and flowers, and that DmCPD was also highly expressed in pedicels. To generate miniature plants, an RNAi expression vector targeting both DmCPD and DmGA20ox was constructed and transformed into chrysanthemum plants. Smaller plant size and slower growth and development of flowers were observed in dual-silenced chrysanthemums. Brassinosteroid and gibberellin contents in leaves and flower buds of transgenic plants were significantly decreased. Furthermore, the expressions of brassinolide-, gibberellin-, and flowering-related genes were down-regulated by varying degrees in dual-silenced plants. These results suggest that DmCPD and DmGA20ox play important roles in plant architecture, and brassinolide and gibberellin are important hormones in controlling plant architecture. This miniaturization strategy provides an efficient approach for generating new varieties of ornamental plants and crops.

Bok choy (Brassica rapa var. chinensis) is an important dietary vegetable cultivated and consumed worldwide for its edible leaves. The purple cultivars rich in health-promoting anthocyanins are usually more eye-catching and valuable. Fifteen kinds of anthocyanins were separated and identified from a purple bok choy cultivar (Zi He) by high-performance liquid chromatography–electrospray ionization tandem mass spectrometry. To investigate the molecular mechanisms underlying anthocyanin accumulation in bok choy, the expression profiles of anthocyanin biosynthetic and regulatory genes were analyzed in seedlings and leaves of the purple cultivar and the green cultivar (Su Zhouqing). Compared with the other tissues, BrTT8 and most of the anthocyanin biosynthetic genes were significantly up-regulated in the leaves and light-grown seedlings of Zi He. The results that heterologous expression of BrTT8 promotes the transcription of partial anthocyanin biosynthetic genes in regeneration shoots of tomato indicate that BrTT8 plays an important role in the regulation of anthocyanin biosynthesis.

The ornamental Brassica oleracea var. acephala f. tricolor is a good winter and spring foliage plant. Plant architecture is an important agronomic trait of plants, especially for ornamental plants with high ornamental and economic value. In this study, three miniature-related genes, BoDWARF, BoGA20ox and BoSP (SELF-PRUNING), were cloned and their tissue-specific expression patterns were analyzed. The results showed that the three genes were all highly expressed in young leaves and flowers, followed by the lateral roots, seeds and stems. To further achieve the purpose of miniaturization of plants, an RNAi expression vector, jointly targeting BoDWARF, BoGA20ox and BoSP, was constructed and transformed into kale plants. Smaller plant size and slower growth and development speed of flowers and roots were observed in jointly silenced kales. Brassinosteroids and gibberellin contents in leaves and flower buds of transgenic plants were significantly decreased. Furthermore, the expressions of brassinolide-, gibberellin- and flowering-related genes were down-regulated by varying degrees in silenced plants. These results suggest that BoDWARF, BoGA20ox and BoSP play important roles in plant architecture, and that brassinolide and gibberellin are important hormones controlling plant growth and architecture. This miniaturization strategy of kale provides an efficient approach for cultivation of new varieties of ornamental plants and crops.

Anthocyanins are one of the largest and most important groups of water-soluble pigments in most species in the plant kingdom. They are flavonoid derivatives and colorful pigments of plant tissues and vegetables. Moreover, anthocyanins exhibit potential antioxidant capacity and can protect plants against biotic and abiotic stresses. In the present study, two transcription factor genes of the anthocyanin biosynthesis pathway, DELILA (Del) and ROSEAL (Ros1), were cloned from snapdragon Antirrhinum majus and heterologously expressed in Brassica napus. Down-stream structural genes in the anthocyanins biosynthesis pathway were significantly up-regulated. Furthermore, the anthocyanin content in the transgenic plant leaves was increased nearly up to tenfold and the antioxidant activity in transgenic leaves was approximately enhanced up to three-fold. Our present study provides a novel approach to enhance B. napus antioxidant activity. Moreover, the present study supplies a potential source to produce anthocyanins from the tissues of transgenic Del/Ros1B. napus plant and yields a new insight into better understanding of the transcriptional regulation of anthocyanin biosynthesis.

In the present study, we designed a novel targeted multi-functional fusion protein LHAD composed of LL-37, FXa recognition peptide, hirudin-12-residue, AAP, and RGD peptide. It was expressed in the Pichia pastoris GS115 strain and purified by affinity chromatography. The in vitro studies suggested that the novel designed protein exhibited antibacterial activity, anti-platelet aggregation and anti-thrombin activities. Moreover, the capability of anti-thrombin was significantly increased compared to that of natural hirudin. Our study may provide a potential approach to design multi-functional drugs for the prevention and management of thrombosis.

•SlMBP11 is ubiquitously expressed in all of the tissues we examined.•SlMBP11 overexpressing plants display reduced plant height and leaf size.•SlMBP11 overexpressing lines display increased axillary buds.•Overexpression lines exhibit a shorter style and split ovary phenotypes.•Overexpression of SlMBP11 delay perianth organ senescence.MADS-domain proteins are important transcription factors that are involved in many biological processes of plants. In the present study, SlMBP11, a member of the AGL15 subfamily, was cloned in tomato plants (Solanum lycopersicon M.). SlMBP11 is ubiquitously expressed in all of the tissues we examined, whereas the SlMBP11 transcription levels were significantly higher in reproductive tissues than in vegetative tissues. Plants exhibiting increased SlMBP11 levels displayed reduced plant height, leaf size, and internode length as well as a loss of dominance in young seedlings, highly branched growth from each leaf axil, and increased number of nodes and leaves. Moreover, overexpression lines also exhibited reproductive phenotypes, such as those having a shorter style and split ovary, leading to polycarpous fruits, while the wild type showed normal floral organization. In addition, delayed perianth senescence was observed in transgenic tomatoes. These phenotypes were further confirmed by analyzing the morphological, anatomical and molecular features of lines exhibiting overexpression. These results suggest that SlMBP11 plays an important role in regulating plant architecture and reproductive development in tomato plants. These findings add a new class of transcription factors to the group of genes controlling axillary bud growth and illuminate a previously uncharacterized function of MADS-box genes in tomato plants.

•SlGID2 gene is ubiquitously expressed in tomato tissues.•Silencing of SlGID2 in tomato displays a dwarf plant and dark-green leaf phenotypes.•SlGID2i transgenic plants are GA insensitive.•SlGID2 may be a positive regulator of GA signaling and promotes GA signal pathway.In plant, F-box protein participates in various signal transduction systems and plays an important role in signaling pathways. Here, a putative F-box protein, namely SlGID2, was isolated from tomato (Solanum lycopersicum). Bioinformatics analyses suggested that SlGID2 shows high identity with F-box proteins from other plant species. Expression pattern analysis showed that SlGID2 gene is ubiquitously expressed in tomato tissues. To study the function of SlGID2 in tomato, SlGID2-silenced (SlGID2i) tomato by RNA interference (RNAi) was generated and displayed a dwarf plant and dark-green leaf phenotypes. The defective stem elongation of SlGID2i lines was not rescued by exogenous GA and its endogenous GA level was higher than wild type, further supporting the observation that SlGID2i transgenic plants are GA insensitive. Furthermore, SlGAST1, the downstream gene of GA signaling, and some cell expansion, division related genes (SlCycB1;1, SlCycD2;1, SlCycA3;1, SlXTH2, SlEXP2, SlKRP4) were down-regulated by SlGID2 silencing. In addition, the expression levels of SlDELLA (a negative regulator of GA signaling) and SlGA2ox1 were decreased, while SlGA3ox1 and SlGA20ox2 transcripts were increased in SlGID2i lines. Thus, we conclude that SlGID2 may be a positive regulator of GA signaling and promotes the GA signal pathway.