The development of hooded awns in barley: From ectopic Kap1 expression to yield potential.

Awns in barley have different shapes including awnless, straight, hooded, crooked, and leafy awns. The hooded awns are characterized by an appendage of the lemma, which forms a trigonal or cap-shaped structure, and even blossoms and yields fruits on barley awn. In the lemma primordia of wild-type (straight awn), cells divide and elongate to form the straight awn. However, in the lemma primordia of KNOX3 mutant (hooded awn), cells divide at various orientations without elongating, and they form hooded awns. This phenomenon is due to the upregulation of KNOX3 expression via insertion of a tandem direct duplication of 305 bp in the intron IV. Here, we summarize the development of barley hooded awn research in the following two aspects: on the one hand, the morphology, development of hooded awns, and the expression regulation of the KNOX3 gene. The latter includes ectopic expression of the KNOX3 gene, gene interactions among awn-related genes, the regulatory relationship between class I KNOX genes and hormones, as well as the influence of abiotic stresses. On the other hand, the potential performance of hooded awns in barley for yield breeding is discussed. Hooded awns have potential application value in forage, which could compensate for the disadvantage of the long straight awn in the barley straw used for feed in modern cultivars. In addition, the hooded awn produces ectopic meristems to develop complete florets, which is an interesting question and helps to understand the development, adaptation, and evolution of plant floral organs.

Genome-wide identification, characterization, and evolutionary analysis of the barley TALE gene family and its expression profiles in response to exogenous hormones.

Three-amino-loop-extension (TALE) family belongs to the homeobox gene superfamily and occurs widely in plants, playing a crucial role in regulating their growth and development. Currently, genome-wide analysis of the TALE family has been completed in many plants. However, the systematic identification and hormone response analysis of the TALE gene family in barley are still lacking. In this study, 21 TALE candidate genes were identified in barley, which can be divided into KNOX and BELL subfamilies. Barley TALE members in the same subfamily of the phylogenetic tree have analogically conserved motifs and gene structures, and segmental duplications are largely responsible for the expansion of the HvTALE family. Analysis of TALE orthologous and homologous gene pairs indicated that the HvTALE family has mainly undergone purifying selective pressure. Through spatial structure simulation, HvKNOX5-HvKNOX6 and HvKNOX5-HvBELL11 complexes are all formed through hydrogen bonding sites on both the KNOX2 and homeodomain (HD) domains of HvKNOX5, which may be essential for protein interactions among the HvTALE family members. Expression pattern analyses reveal the potential involvement of most HvTALE genes in responses to exogenous hormones. These results will lay the foundation for regulation and function analyses of the barley TALE gene family in plant growth and development by hormone regulation.

A new norsesquiterpenoid from Ligularia virgaurea.

A new eremophilane norsesquiterpenoid (1), together with a known eremophilane sesquiterpenoid (2), was isolated from the leaves of Ligularia virgaurea. The structure of 1 was elucidated by a combination of spectroscopic analysis (IR, 1D NMR, 2D NMR, and HR-ESI-MS), and its absolute configuration was determined by a single-crystal X-ray diffraction experiment (with copper radiation). The known compound 2 was identified by comparison of its physical and spectral data with those reported in the literature. Compound 1 was assayed for its cytotoxic activities against human cervical carcinoma cell (HeLa) and human small cell lung cancer cell (NCI-446) lines.

[Repetition of teaching contents between genetics and relative courses in agricultural and forestry colleges and approaches to solving the problem].

Genetics is one of the main courses in agricultural and forestry colleges. However, there is large repetition of teaching contents and joining problems between genetics and the relative courses. The negative effects of above problems are discussed in this paper. In order to relieve the conflict between the increase of genetics contents and the decrease of teaching hours in genetics teaching of undergraduates and provide reference for future textbook compilation, some approaches on solving repetition of teaching content and suggestions on joining problems are put forward.