[Lodging in wheat: genetic and environmental factors and ways of overcoming]

Integrated transcriptomic and proteomic analyses of two sugarcane (Saccharum officinarum Linn.) varieties differing in their lodging tolerance

BACKGROUND

Lodging seriously affects sugarcane stem growth and sugar accumulation, reduces sugarcane yield and sucrose content, and impedes mechanization. However, the molecular mechanisms underlying sugarcane lodging tolerance remain unclear. In this study, comprehensive transcriptomic and proteomic analyses were performed to explore the differential genetic regulatory mechanisms between upright (GT42) and lodged (GF98-296) sugarcane varieties.

RESULTS

The stain test showed that GT42 had more lignin and vascular bundles in the stem than GF98-296. The gene expression analysis revealed that the genes that were differentially expressed between the two varieties were mainly involved in the phenylpropanoid pathway at the growth stage. The protein expression analysis indicated that the proteins that were differentially expressed between the two varieties were related to the synthesis of secondary metabolites, the process of endocytosis, and the formation of aminoacyl-tRNA. Time-series analysis revealed variations in differential gene expression patterns between the two varieties, whereas significant protein expression trends in the two varieties were largely consistent, except for one profile. The expression of CYP84A, 4CL, and CAD from the key phenylpropanoid biosynthetic pathway was enhanced in GT42 at stage 2 but suppressed in GF98-296 at the growth stage. Furthermore, the expression of SDT1 in the nicotinate and nicotinamide metabolism was enhanced in GT42 cells but suppressed in GF98-296 cells at the growth stage.

CONCLUSION

Our findings provide reference data for mining lodging tolerance-related genes that are expected to facilitate the selective breeding of sugarcane varieties with excellent lodging tolerance.

Exogenous brassinosteroids promotes root growth, enhances stress tolerance, and increases yield in maize

Brassinosteroids (BRs) regulate of maize (Zea mays L.) growth, but the underlying molecular mechanism remains unclear. In this study, we used a multi-disciplinary approach to determine how BRs regulate maize morphology and physiology during development. Treatment with the BRs promoted primary root the elongation and growth during germination, and the early development of lateral roots. BRs treatment during the middle growth stage increased the levels of various stress resistance factors, and enhanced resistance to lodging, likely by protecting the plant against stem rot and sheath rot. BRs had no significant effect on plant height during late growth, but it increased leaf angle and photosynthetic efficiency, as well as yield and quality traits. Our findings increase our understanding of the regulatory effects of BR on maize root growth and development and the mechanism by which BR improves disease resistance, which could further the potential for using BR to improve maize yield.

Scientific breeding of winter bread wheat in the Non-Сhernozem zone of Russia: the history, methods and results

The article describes the main stages and achievements of the breeding of winter bread wheat (Triticum aestivum L.) in the Non-Chernozem zone for more than a century. The beginning of breeding work was laid by D.L. Rudzinsky on the experimental field of the Moscow Agricultural Institute. Beginning from the 1940s, under the leadership of Academician N.V. Tsitsin, and then Prof. G.D. Lapchenko, the method of distinct hybridization with blue wheatgrass (Agropyron glaucum (Desf. ex DC.) Roem. & Schult.) was actively used. The resulting wheat-wheatgrass hybrids had an average winter hardiness, increased grain quality and productivity. Cultivar Zarya developed in the 1970s (by individual selection from the F3 cross combination of cv. Mironovskaya 808×line 126/65 (in the pedigree of this line, there is a wheat-wheatgrass hybrid PPG 599)) had a high yield and was widely used in further crosses. In the 1980s, Academician B.I. Sandukhadze achieved a significant increase in yield by using the method of intermittent backcrosses due to the producing of varieties with a new morphoecotype (cvs Inna, Pamyati Fedina, etc.), namely, winter-hardy, short stemmed (dwarf), and productive. Cultivar Moskovskaya 39 (registration in 1999) was referred to strong wheat, with a stable protein content of 15-16 %, gluten 30-35 %. Produced in the 2000s, cvs Moskovskaya 56, Nemchinovskaya 57, Galina, Nemchinovskaya 24, Nemchinovskaya 17, and Moskovskaya 40 have a high adaptability to the environment of the region; give a high yield and quality of grain. The area of crops of these cultivars in Russia occupies more than 2 million ha. The current trends in wheat breeding are indicated, the production yield of commercial cultivars of breeding by the Federal Research Center "Nemchinovka" over 12.0 tons per ha and the protein content in the grain up to 17 % are shown. As a result of succession, originality and application of the methodology of scientific breeding, the yield of winter bread wheat in the period from the beginning of the last century to the present has increased from 1.0 to 12.0 and more tons per ha.