Deciphering the evolution and biogeography of ant-ferns Lecanopteris s.s.

Southeast Asia is a biodiversity hotspot characterized by a complex paleogeography, and its Polypodiopsida flora is particularly diverse. While hybridization is recognized as common in ferns, further research is needed to investigate the relationship between hybridization events and fern diversity. Lecanopteris s.

Transgenic barley with overexpressed PTrx increases aluminum resistance in roots during germination.

A transgenic barley line (LSY-11-1-1) with overexpressed Phalaris coerulescens thioredoxin gene (PTrx) was employed to measure the growth, protein oxidation, cell viability, and antioxidase activity in barley roots during germination on the presence of 2 mmol/L AlCl(3) on filter paper. The results show that (1) compared with the non-transgenic barley, LSY-11-1-1 had enhanced root growth, although both were seriously inhibited after AlCl(3) treatment; (2) the degree of protein oxidation and loss of cell viability in roots of LSY-11-1-1 were much less than those in roots of non-transgenic barley, as reflected by lower contents of protein carbonyl and Evans blue uptakes in LSY-11-1-1; (3) activities of catalase (CAT), glutathione peroxidase (GPX), ascorbate peroxidase (APX), and glutathione reductase (GR) in LSY-11-1-1 root tips were generally higher than those in non-transgenic barley root tips, although these antioxidase activities gave a rise to different degrees in both LSY-11-1-1 and non-transgenic barley under aluminum stress. These results indicate that overexpressing PTrx could efficiently protect barley roots from oxidative injury by increasing antioxidase activity, thereby quenching ROS caused by AlCl(3) during germination.

The level of expression of thioredoxin is linked to fundamental properties and applications of wheat seeds.

Work with cereals (barley and wheat) and a legume (Medicago truncatula) has established thioredoxin h (Trx h) as a central regulatory protein of seeds. Trx h acts by reducing disulfide (S-S) groups of diverse seed proteins (storage proteins, enzymes, and enzyme inhibitors), thereby facilitating germination. Early in vitro protein studies were complemented with experiments in which barley seeds with Trx h overexpressed in the endosperm showed accelerated germination and early or enhanced expression of associated enzymes (alpha-amylase and pullulanase).

Protective role of exogenous nitric oxide against oxidative-stress induced by salt stress in barley (Hordeum vulgare).

To probe into the potential of relieving the oxidative damage of salt stress, we investigated the protective role of nitric oxide on barley under salt stress. Salt stress resulted in increased ion leakage, lipid peroxidation and protein oxidation in barley leaves. Simultaneous treatments of barley leaves with 50 microM sodium nitroprusside, a nitric oxide donor, alleviated the damage of salt stress, reflected by decreased ion leakage, and malendialdehyde (MDA), carbonyl, and hydrogen peroxide content in barley leaves.

[Effects of antisense-thioredoxin s gene on expression of endogenous thioredoxin h gene in transgenic wheat seed].

To clarify the function mechanism of antisense-thioredoxin s (anti-trxs) gene in transgenic wheat, the expression pattern of endogenous trxh gene in transgenic line 01TY70-1-17-5 and non-transgenic cultivar 'Yumai 70' were detected by semi-quantitative RT-PCR using wheat actin gene as the endogenous control. The results of analysis of transgenic and non-transgenic seeds in different maturation periods, different tissues and different germinating processes indicated that the mRNA transcript amounts of trxh gene in transgenic line seed were lowered distinctly, though the trxh gene mRNA transcript level varied greatly in different developing and germination stages. The mRNA transcript amounts of trxh gene in transgenic line seed were significantly lower than the control seeds by 20.