Influence of high-molecular-weight glutenin subunit deletions at the Glu-A1 and Glu-D1 loci on protein body development, protein components and dough properties of wheat(Triticum aestivum L.)

High-molecular-weight glutenin subunits(HMW-GSs) play a critical role in determining the viscoelastic properties of wheat. As the organelle where proteins are stored, the development of protein bodies(PBs) reflects the status of protein synthesis and also affects grain quality to a great extent. In this study, with special materials of four near-isogenic lines in a Yangmai 18 background we created, the effects of Glu-A1 and Glu-D1 loci deletions on the development and morphological properties of the protein body, protein components and dough properties were investigated. The results showed that the deletion of the HMW-GS subunit delayed the development process of the PBs, and slowed the increases of volume and area of PBs from 10 days after anthesis(DAA) onwards. In contrast, the areas of PBs at 25 DAA, the middle or late stage of endosperm development, showed no distinguishable differences among the four lines. Compared to the wild type and single null type in Glu-A1, the ratios of HMW-GSs to low-molecular-weight glutenin subunits(LMW-GSs), glutenin macropolymer(GMP) content, mixograph parameters as well as extension parameters decreased in the single null type in Glu-D1 and double null type in Glu-A1 and Glu-D1, while the ratios of gliadins(Gli)/glutenins(Glu) in those types increased. The absence of Glu-D1 subunits decreased both dough strength and extensibility significantly compared to the Glu-A1 deletion type. These results provide a detailed description of the effect of HMW-GS deletion on PBs, protein traits and dough properties, and contribute to the utilization of Glu-D1 deletion germplasm in weak gluten wheat improvement for use in cookies, cakes and southern steamed bread in China and liquor processing.

Accumulation characteristic of protein bodies in different regions of wheat endosperm under drought stress

The structural characteristics of protein body accumulation in different endosperm regions of hard wheat cultivar （XM33） and soft wheat cultivar （NM13） under drought stress were investigated. Drought stress treatment was implemented from plant regreening to the caryopsis mature stage. Microscope images of endosperm cells were obtained using resin semi- thin slice technology to observe the distribution and relative area of protein body （PB）. Compared with NM13, relative PB area of XM33 was significantly higher in sub-aleurone endosperm region. The amount of accumulation, including the size and relative area of PB, in two wheat cultivars was higher in sub-aleurone region than that in central region at 18 days post anthesis （DPA）. Drought stress significantly enhanced the sizes and relative areas of PBs in the dorsal and abdominal endosperms in two wheat cultivars. Particularly for dorsal endosperm, drought stress enhanced the relative PB area at 18 DPA and NM13 （5.0% vs. 6.73%） showed less enhancement than XM33 （5.49% vs. 8.96%）. However, NM13 （9.58% vs. 12.02%） showed greater enhancement than XM33 （10.25% vs. 11.7%） at 28 DPA. The protein content in the dorsal and abdominal endosperms of the two wheat cultivars decreased at 12 DPA and then increased until 38 DPA. Drought stress significantly increased the protein contents in the two main regions. From 12 to 38 DPA, the amount of PB accumulation and the protein content were higher in XM33 than those in NM13. The results revealed that PB distribution varied in different endosperm tissues and that the amount of PB accumulation was remarkably augmented by drought stress.

Feeding Effect of Growing-Finishing Pigs under Fine Division of Feeding Stages

In order to study the feeding effect of fine division of feeding stages on the growing-finishing pigs,96 healthy Duroc × Landrace ×Yorkshire hybrid commercial pigs with similar age in days,size,and body weight about 15 kg,half boars and half sows,randomly divided into3 treatments( each treatment repeated 4 times,and each repetition 8 pigs). According to the body weight division standard,three stages,four stages,and five stages of feeding were adopted separately. The daily ration of with different nutrition levels was used,body weight and feed consumption were measured,and effects of different feeding methods on body weight increase,feed utilization,and economic benefits of growing-finishing pigs. The results showed that compared with the three-stage feeding,the body weight of five-stage and four-stage feeding increased by 4. 18%( P < 0. 01) and 2. 41%( P < 0. 05),respectively,and the body weight of five-stage feeding increased by 1. 74%( P < 0. 05) compared with that of four-stage feeding; the daily feed consumption of five-stage and four-stage feeding increased 3. 10%( P < 0. 01) and 1. 70%(P <0. 01),respectively,and the daily feed consumption of five-stage feeding was 1. 37% higher than that of four-stage feeding. The feed cost of five-stage feeding and four-stage feeding increased 3. 32%( P < 0. 01) and 1. 61%( P < 0. 05) separately,and the feed cost of five-stage feeding was 1. 69% higher than that of four-stage feeding( P < 0. 01). The income from average body weight increase of five-stage and fourstage feeding increased by 5. 47%( P < 0. 01) and 3. 59%( P < 0. 01) respectively,and the benefit of average body weight increase of fivestage feeding was 1. 81% higher than that of four-stage feeding( P > 0. 05). The crude protein consumption from average body weight increase of five-stage and four-stage feeding decreased by 2. 28%( P < 0. 01) and 1. 68%( P < 0. 01),respectively; the crude protein consumption from average body weight increase of five-stage feeding was 0. 67% lower than that of four-stage feeding; the feed conversion ratio of five-stage feeding,four-stage feeding,and three-stage feeding was 2. 92,2. 93,and 2. 95 respectively. The results showed that compared with the threestage feeding,the four-stage and five-stage feeding could significantly increase the body weight of the growing-finishing pigs,improve the feed utilization level and improve the economic benefits,and the effect of five-stage feeding was better than the four-stage feeding.

Specialized endoplasmic reticulum-derived vesicles in plants:Functional diversity,evolution,and biotechnological exploitation

A central role of the endoplasmic reticulum(ER)is the synthesis,folding and quality control of secretory proteins.Secretory proteins usually exit the ER to enter the Golgi apparatus in coat protein complex II(COPII)-coated vesicles before transport to different subcellular destinations.However,in plants there are specialized ER-derived vesicles(ERDVs)that carry specific proteins but,unlike COPII vesicles,can exist as independent organelles or travel to the vacuole in a Golgi-independent manner.These specialized ERDVs include protein bodies and precursor-accumulating vesicles that accumulate storage proteins in the endosperm during seed development.Specialized ERDVs also include precursor protease vesicles that accumulate amino acid sequence KDEL-tailed cysteine proteases and ER bodies in Brassicales plants that accumulate myrosinases that hydrolyzes glucosinolates.These functionally specialized ERDVs act not only as storage organelles but also as platforms for signal-triggered processing,activation and deployment of specific proteins with important roles in plant growth,development and adaptive responses.Some specialized ERDVs have also been exploited to increase production of recombinant proteins and metabolites.Here we discuss our current understanding of the functional diversity,evolutionary mechanisms and biotechnological application of specialized ERDVs,which are associated with some of the highly remarkable characteristics important to plants.