Cloning and expression of 1-aminocyclopropane-1-carboxylate oxidase cDNA induced by thidiazuron during somatic embryogenesis of alfalfa (Medicago sativa).

Embryogenic callus (EC) induced from petioles of alfalfa (Medicago sativa L. cv. Jinnan) on B5h medium turned green, compact and non-embryogenic when the kinetin (KN) in the medium was replaced partially or completely by thidiazuron (TDZ).

Over-expression of mango (Mangifera indica L.) MiARF2 inhibits root and hypocotyl growth of Arabidopsis.

An auxin response factor 2 gene, MiARF2, was cloned in our previous study [1] from the cotyledon section of mango (Mangifera indica L. cv. Zihua) during adventitious root formation, which shares an 84% amino acid sequence similarity to Arabidopsis ARF2.

Cloning and expression of resistance gene analogs (RGAs) from wild banana resistant to banana Fusarium wilt.

Wild banana species are essential natural gene pools for banana improvement. In this study, six RGAs about 500 bp were obtained from leaves of Musa acuminata, a wild banana shown to be resistant to banana Fusarium wilt race 4, by PCR amplification with degenerate primers designed according to the conserved NBS motif and serine/threonine kinase domain of plant resistance (R) genes. Among these RGAs, the deduced amino acids of WNB1 and WNB2 contain NB-ARC domain and WNB1 can be translated into polypeptide uninterrupted by stop codons.

Plant miRNAs and abiotic stress responses.

MicroRNAs (miRNAs) are endogenous approximate 22 nucleotide (nt) small non-coding regulatory RNAs that play important roles in plants by targeting mRNAs for cleavage or translational repression. Plant miRNAs were described 10 years later than animal miRNAs did; there are some differences between them in terms of biogenesis and mechanism of function. Furthermore, plant miRNAs have been shown to be involved in various stress responses, such as oxidative, mineral nutrient deficiency, dehydration, and even mechanical stimulus.

Highly efficient Agrobacterium-mediated transformation of embryogenic cell suspensions of Musa acuminata cv. Mas (AA) via a liquid co-cultivation system.

A high efficient protocol of Agrobacterium-mediated transformation of Musa acuminata cv. Mas (AA), a major banana variety of the South East Asia region, was developed in this study. Male-flower-derived embryogenic cell suspensions (ECS) were co-cultivated in liquid medium with Agrobacterium strain EHA105 harboring a binary vector pCAMBIA2301 carrying nptII and gusA gene in the T-DNA.

Induction and cryopreservation of embryogenic cultures from nucelli and immature cotyledon cuts of mango (Mangifera indica L. var Zihua).

In this paper, we described the direct somatic embryogenesis from both immature cotyledon cuts and nucelli in the same mango cultivar (Mangifera indica L. var Zihua), studied the effect of growth conditions of embryogenic cultures (EMs) on cryopreservation and compared the cryopreservation response of EMs induced from these two different explants. Histological studies demonstrated that EMs derived from nucelli could be induced directly from epidermal cells of both sides of nucelli, whereas EMs derived from cotyledon cuts were induced only from epidermal cells of the adaxial side of the cotyledons.

[Identification of an auxin response factor-like protein cDNA from mango cotyledon section].

Auxin-responsive elements (AuxRE) interact with a new class of plant-specific transcription factors, auxin response factors (ARFs). Some of ARFs have been shown to repress or activate expression of genes with an AuxRE promotor element. In Arabidopsis, ARFs play important roles in early embryo development and vascular strand formation (ARF5), floral patterning (ARF3) and photo- and gravitropic responses (ARF7).

[Studies on the cell growth, differentiation and terpene lactone accumulation in Ginkgo biloba cell suspension cultures].

To provide supports for Ginkgo biloba cell engineering for production of Terpene lactones (Ginkgolides and bilobalide), the cell suspension were established from calli induced from zygote embryos and stems of 30-day-old seedlings respectively. The relationship between cell growth, differentiation and the terpene lactone accumulation in these suspension cultures were investigated. HPLC determination indicated that, the ginkgolide B was found in the embryo derived cell suspension cultures at 0.

[Establishment of embryogenic cell suspension culture and plant regeneration of edible banana Musa acuminata cv. Mas (AA)].

Conventional breeding for dual resistance of disease and pest of Musa cultivars remains a difficult endeavor, as the plant is polyploidic and high in sterility. Biotechnological techniques, eg., genetic engineering, in vitro mutation breeding, or protoplast fusion, may overcome the difficulties and improve the germplasm.

[Cloning of cDNA fragments related to adventitious root formation from mango cotyledon section].

Two cut surfaces of mango cotyledon (distal and proximal cut surfaces) showed different capability of adventitious root formation, only proximal cut surface could be induced to form the roots and the distal cut surface did not. cDNA fragments related to adventitious root formation from the cut sections were isolated with suppressive subtractive hybridization. The forward substracted cDNA library was constructed using the cDNAs of distal (non-rooting) cut surface as driver and the cDNAs of proximal (rooting) cut surface as tester.

The effect of AOA on ethylene and polyamine metabolism during early phases of somatic embryogenesis in Medicago sativa.

Changes in the levels of ethylene, 1-aminocyclopropane-1-carboxylic acid (ACC), 1-(malonylamino)cyclopropane-1-carboxylic acid (MACC) and polyamines were simultaneously investigated during the early phases of alfalfa somatic embryogenesis. These included the period of induction and subculture of callus, and 3- and 7-day suspension cultures for the induction of somatic embryogenesis. The polyamines contained in the embryogenic callus were found to include putrescine (Put), spermidine (Spd) and spermine (Spm), but the level of Spm was much less than that of Put and Spd.