Spinach (Spinacia oleracea L.) develops leaf rosettes under short-day conditions, and starts reproductive growth including bolting and flowering under long-day conditions. Japanese people prefer Oriental spinach that ...Spinach (Spinacia oleracea L.) develops leaf rosettes under short-day conditions, and starts reproductive growth including bolting and flowering under long-day conditions. Japanese people prefer Oriental spinach that bolts easily with a shorter photoperiod than European spinach. This is one of the main reasons that Oriental spinach is difficult to grow year-round. In order to understand spinach flowering mechanisms and obtain knowledge for spinach breeding, we isolated one CONSTANS-like (COL) and two FLOWERING LOCUS T (FT) homologs, which are key components of photoperiodic regulation of flowering time, from a Japanese cultivar. The expression of SoCOL1 showed diurnal rhythm with the highest expression at the end of the dark cycle. This diurnal rhythm is similar to the expression of BvCOL1 from sugar beet (Beta vulgaris), whose flower-promoting effect was observed when overexpressed in Arabidopsis. Phylogenetic analysis showed that SoCOL1 is the closest homolog of BvCOL1, suggesting that SoCOL1 is an ortholog of BvCOL1. SoFT1 and SoFT2 are closely related to BvFT1 and BvFT2, respectively. The expression of SoFT1 and SoFT2 were induced in advance of flower bud formation after changing the photoperiod, but the expression level of SoFT1 was much lower than SoFT2. Currently, we are speculating that SoFT2 is a flower-promoting factor of spinach, and that SoFT1 has a role in light signaling because the expression of SoFT1 showed a diurnal rhythm.展开更多
We have done a comparative study of ion status, growth and biochemical parameters in shoots and roots of seablite (Suaeda altissima (L.) Pall.) and spinach (Spinacia oleracea L.) grown with different salinity levels i...We have done a comparative study of ion status, growth and biochemical parameters in shoots and roots of seablite (Suaeda altissima (L.) Pall.) and spinach (Spinacia oleracea L.) grown with different salinity levels in the medium (0.5 - 750 mМ). A distinctive feature of the halophyte was a high Na+ content in tissues at its low concentration in the medium (0.5 mM). In these conditions, Na+ accumulation in seablite roots was four-fold higher than in spinach roots, and Na+ content in seablite leaves was almost 20-fold higher than in spinach. Together with an increase in sodium concentration in the medium, K+ content decreased six-fold in seablite leaves, while in spinach it did not decrease so drastically. We can suppose that in the halophyte, some processes occur only in the presence of sodium, and these functions of sodium cannot be fully fulfilled by potassium. Analysis of protein and total nitrogen content in tissues shows that at high salinity, the ability to synthesize non-protein nitrogen-containing compounds increases in the halophyte and decreases in the glycophyte. Data on proline content dynamics show that its increase in tissues of spinach (salinity levels 150 and 250 mМ) and seablite (salinity levels 0.5 and 750 mМ) is an indicator of plant injury. In seablite and spinach, proline is not a major osmoregulator. Its concentration both in roots and leaves was no more than 2.5 μmol/g fresh weight. The data presented in this work concern the accumulation and distribution of Na+, Cl?, K+ and ions, as well as growth and biochemical parameters. Our data show that the development of adaptation reactions in the whole plants in the conditions of high salinity is determined by morphofunctional systems and their interaction.展开更多
文摘Spinach (Spinacia oleracea L.) develops leaf rosettes under short-day conditions, and starts reproductive growth including bolting and flowering under long-day conditions. Japanese people prefer Oriental spinach that bolts easily with a shorter photoperiod than European spinach. This is one of the main reasons that Oriental spinach is difficult to grow year-round. In order to understand spinach flowering mechanisms and obtain knowledge for spinach breeding, we isolated one CONSTANS-like (COL) and two FLOWERING LOCUS T (FT) homologs, which are key components of photoperiodic regulation of flowering time, from a Japanese cultivar. The expression of SoCOL1 showed diurnal rhythm with the highest expression at the end of the dark cycle. This diurnal rhythm is similar to the expression of BvCOL1 from sugar beet (Beta vulgaris), whose flower-promoting effect was observed when overexpressed in Arabidopsis. Phylogenetic analysis showed that SoCOL1 is the closest homolog of BvCOL1, suggesting that SoCOL1 is an ortholog of BvCOL1. SoFT1 and SoFT2 are closely related to BvFT1 and BvFT2, respectively. The expression of SoFT1 and SoFT2 were induced in advance of flower bud formation after changing the photoperiod, but the expression level of SoFT1 was much lower than SoFT2. Currently, we are speculating that SoFT2 is a flower-promoting factor of spinach, and that SoFT1 has a role in light signaling because the expression of SoFT1 showed a diurnal rhythm.
文摘We have done a comparative study of ion status, growth and biochemical parameters in shoots and roots of seablite (Suaeda altissima (L.) Pall.) and spinach (Spinacia oleracea L.) grown with different salinity levels in the medium (0.5 - 750 mМ). A distinctive feature of the halophyte was a high Na+ content in tissues at its low concentration in the medium (0.5 mM). In these conditions, Na+ accumulation in seablite roots was four-fold higher than in spinach roots, and Na+ content in seablite leaves was almost 20-fold higher than in spinach. Together with an increase in sodium concentration in the medium, K+ content decreased six-fold in seablite leaves, while in spinach it did not decrease so drastically. We can suppose that in the halophyte, some processes occur only in the presence of sodium, and these functions of sodium cannot be fully fulfilled by potassium. Analysis of protein and total nitrogen content in tissues shows that at high salinity, the ability to synthesize non-protein nitrogen-containing compounds increases in the halophyte and decreases in the glycophyte. Data on proline content dynamics show that its increase in tissues of spinach (salinity levels 150 and 250 mМ) and seablite (salinity levels 0.5 and 750 mМ) is an indicator of plant injury. In seablite and spinach, proline is not a major osmoregulator. Its concentration both in roots and leaves was no more than 2.5 μmol/g fresh weight. The data presented in this work concern the accumulation and distribution of Na+, Cl?, K+ and ions, as well as growth and biochemical parameters. Our data show that the development of adaptation reactions in the whole plants in the conditions of high salinity is determined by morphofunctional systems and their interaction.
