Strawberry tonoplast transporter, FaVPT1, controls phosphate accumulation and fruit quality.

Phosphorus (P) is essential for plant growth and development, and the vacuole is an important organelle for phosphate storage. However, the tonoplast phosphate transporter in fleshy fruits remains unknown. In this study, based on the strawberry (Fragaria × ananassa) fruit transcriptome data, a tonoplast-localized vacuolar phosphate transporter with SPX and major facilitator superfamily domains, FaVPT1, was identified. FaVPT1 expression was highest in the fruits and could be induced by sucrose. Using transient transgenic systems in strawberry fruit, the downregulation and upregulation of FaVPT1 inhibited and promoted ripening, respectively, and affected phosphate contents, fruit firmness, sugar and anthocyanin contents, and ripening-related gene transcription. FaVPT1 could rescue Pi absorption in both yeast and the Arabidopsis atvpt1 mutant, confirming the similar function of FaVPT1 and AtVPT1, a previously identified tonoplast phosphate transporter in Arabidopsis. The Escherichia coli-expressed SPX domain of FaVPT1 could strongly bind to InsP6 with a Kd of 3.5 µM. The results demonstrate that FaVPT1 is a tonoplast phosphate transporter and regulates strawberry fruit ripening and quality, to a large extent, via sucrose.

Characterization of the hot pepper (Capsicum frutescens) fruit ripening regulated by ethylene and ABA.

BACKGROUND: Ripening of fleshy fruits has been classically defined as climacteric or non-climacteric. Both types of ripening are controlled by plant hormones, notably by ethylene in climacteric ripening and by abscisic acid (ABA) in non-climacteric ripening. In pepper (Capsicum), fruit ripening has been widely classified as non-climacteric, but the ripening of the hot pepper fruit appears to be climacteric. To date, how to regulate the hot pepper fruit ripening through ethylene and ABA remains unclear. RESULTS: Here, we examined ripening of the hot pepper (Capsicum frutescens) fruit during large green (LG), initial colouring (IC), brown (Br), and full red (FR) stages. We found a peak of ethylene emission at the IC stage, followed by a peak respiratory quotient at the Br stage. By contrast, ABA levels increased slowly before the Br stage, then increased sharply and reached a maximum level at the FR stage. Exogenous ethylene promoted colouration, but exogenous ABA did not. Unexpectedly, fluridone, an inhibitor of ABA biosynthesis, promoted colouration. RNA-sequencing data obtained from the four stages around ripening showed that ACO3 and NCED1/3 gene expression determined ethylene and ABA levels, respectively. Downregulation of ACO3 and NCED1/3 expression by virus-induced gene silencing (VIGS) inhibited and promoted colouration, respectively, as evidenced by changes in carotenoid, ABA, and ethylene levels, as well as carotenoid biosynthesis-related gene expression. Importantly, the retarded colouration in ACO3-VIGS fruits was rescued by exogenous ethylene. CONCLUSIONS: Ethylene positively regulates the hot pepper fruit colouration, while inhibition of ABA biosynthesis promotes colouration, suggesting a role of ABA in de-greening. Our findings provide new insights into processes of fleshy fruit ripening regulated by ABA and ethylene, focusing on ethylene in carotenoid biosynthesis and ABA in chlorophyll degradation.

A leu-rich repeat receptor-like protein kinase, FaRIPK1, interacts with the ABA receptor, FaABAR, to regulate fruit ripening in strawberry.

Strawberry (Fragaria×ananassa) is a model plant for studying non-climacteric fruit ripening regulated by abscisic acid (ABA); however, its exact molecular mechanisms are yet not fully understood. In this study, a predicted leu-rich repeat (LRR) receptor-like kinase in strawberry, red-initial protein kinase 1 (FaRIPK1), was screened and, using a yeast two-hybrid assay, was shown to interact with a putative ABA receptor, FaABAR. This association was confirmed by bimolecular fluorescence complementation and co-immunoprecipitation assays, and shown to occur in the nucleus. Expression analysis by real-time PCR showed that FaRIPK1 is expressed in roots, stems, leaves, flowers, and fruit, with a particularly high expression in white fruit at the onset of coloration. Down-regulation of FaRIPK1 expression in strawberry fruit, using Tobacco rattle virus-induced gene silencing, inhibited ripening, as evidenced by suppression of ripening-related physiological changes and reduced expression of several genes involved in softening, sugar content, pigmentation, and ABA biosynthesis and signaling. The yeast-expressed LRR and STK (serine/threonine protein kinase) domains of FaRIPK1 bound ABA and showed kinase activity, respectively. A fruit disc-incubation test revealed that FaRIPK1 expression was induced by ABA and ethylene. The synergistic action of FaRIPK1 with FaABAR in regulation of strawberry fruit ripening is discussed.

[Anatomic investigation of the pedicle fat grafts with the third lumbar segmental artery and its application in reoperation for lumbar disc herniation].

OBJECTIVE: To investigate the blood supply of the pedicle fat grafts with the third lumbar segmental artery and its clinical effects on reoperation for lumbar disc herniation. METHODS: Twelve sides of 6 adult cadaver examples were contributed to investigate the courser of lumbar segmental vessels and the distribution of hypodermic capillary net of the dorsal branch of the third lumbar segmental artery. From January 2000 to January 2007,49 patients needed reoperation to treat lumbar disc herniation,including 26 males and 23 females with an average age of 55.6 years (ranged from 39 to 70 years). Duration between two operations ranged from 8 months to 15 years with an average of 6.9 years. Reoperative reasons included recurrent lumbar disc protrusion(30 cases)postoperative epidural scar formation (17 cases), postoperative epidural cyst formation (2 cases). Of them,9 patients underwent posterior lumbar interbody fusion at the second operation. The pedicle fat grafts with the third lumbar segmental artery were covered on the sites of the laminectomy in these patients. After negative pressure drainage tube were pulled out, 2 ml Chitsan were injected to the sites of the laminectomy and around epidural nerve root through epidural catheter. VAS score and the Oswestry Disability Index (ODI) were used to assess clinical outcomes before and after operation. RESULTS: The courser of third lumbar segmental vessels were invariant at the lateral face of the lumbar vertebral body. The dorsal branch of the third lumbar segmental artery penetrated thoracolumbar fascia and formed rich hypodermic capillary net in the region. All patients were followed up from 5 to 8 years with an average of 5.6 years. VAS score of low back pain and leg pain decreased respectively from preoperative 7.6 +/- 1.2, 8.9 +/- 0.9 to 3.6 +/- 0.5, 3.0 +/- 0.4 at final follow-up (P < 0.01); and ODI score decreased from preoperative 44.1 +/- 6.2 to 13.9 +/- 3.6 at final follow-up (P < 0.01). According to ODI score to evaluate the clinical outcomes, 29 cases got excellent results, 11 good, 7 fair, 2 poor. CONCLUSION: The pedicle fat grafts with the third lumbar segmental artery and Chitsan can reduce epidural scar formation and prevent peridural fibrosis and adhesion and improve clinical effects of reoperation for lumbar disc herniation.