Candidate regulators of Early Leaf Development in Maize Perturb Hormone Signalling and Secondary Cell Wall Formation When Constitutively Expressed in Rice

All grass leaves are strap-shaped with a series of parallel veins running from base to tip, but the distance between each pair of veins, and the cell-types that develop between them, differs depending on whether the plant performs C or C photosynthesis. As part of a multinational effort to introduce C traits into rice to boost crop yield, candidate regulators of C leaf anatomy were previously identified through an analysis of maize leaf transcriptomes. Here we tested the potential of 60 of those candidate genes to alter leaf anatomy in rice. In each case, transgenic rice lines were generated in which the maize gene was constitutively expressed. Lines grouped into three phenotypic classes: (1) indistinguishable from wild-type; (2) aberrant shoot and/or root growth indicating possible perturbations to hormone homeostasis; and (3) altered secondary cell wall formation. One of the genes in class 3 defines a novel monocot-specific family. None of the genes were individually sufficient to induce C -like vein patterning or cell-type differentiation in rice. A better understanding of gene function in C plants is now needed to inform more sophisticated engineering attempts to alter leaf anatomy in C plants

ダイズにおけるプロアントシアニジン含量およびラジカル消去能の遺伝的制御

京都大学0048新制・課程博士博士(農学)甲第15426号農博第1811号新制||農||979(附属図書館)学位論文||H22||N4525(農学部図書室)27904京都大学大学院農学研究科農学専攻(主査)教授 谷坂 隆俊, 教授 冨永 達, 教授 白岩 立彦学位規則第4条第1項該当Doctor of Agricultural ScienceKyoto UniversityDA

Alcohol dehydrogenase (ADH) activity in soybean (Glycine max [L.] Merr.) under flooding stress

Sowing time of soybean (Glycine max [L.] Merr.) often coincides with the early onset of rainy season. Germinating seedsencounter a transient to prolonged period of water-logging that causes anoxia (absence of oxygen) and hypoxia (insufficientoxygen) resulting in poor germination. This reduces crop stability and yield. One of the factors responsible for flood tolerance isactivity of alcohol dehydrogenase (ADH) during flood. The effect of ADH activity during flooding and difference in floodtolerance level were investigated using two soybean cultivars, Peking and Tamahomare, and their F9 recombinant inbred lines(RILs). Tamahomare showed higher ADH activity than Peking. There was a great variation in ADH activity among the RILs.QTL analysis detected five QTLs for ADH activity (qAas1-5) on five linkage groups, LG_A2, D1a, F, K and L. The QTL qAas4was close to a QTL for shoot damage and conductivity of germinating seeds after flooding treatment

Diversity of proanthocyanidin content in soybean landraces

Proanthocyanidins (PAs) are natural plant antioxidants, whose radical scavenging activities (RSA) degrade harmful free radicals. In the current study, PA contents were analyzed in 52 soybean [Glycine max (L) Merril] landraces having different seed coat colors. PA was extracted by HCl-Butanol method; RSA was determined by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method and quantified using spectrophotometer. Soybean cultivar KaiFengKuoZhuangqingDou had the highest PA content, 946 ABS.ml g-1, followed by Peking, 860 ABS.ml g-1. Both the cultivars had black seed coats. Chasengoku 81Go had the highest PA content (485 ABS.ml g-1) among the landraces with brown seed coat color. In landraces with green seed coats, PA content ranged from 1 to 6 ABS.ml g-1. In landraces with yellow seed coats PA content ranged from 0 to 10 ABS.ml g-1. The RSA was directly proportional to PA content with a high correlation coefficient (r2 = 0.9724), so PA content contributed highly to RSA. Reasons for these wide variations in PA content and RSA within the same colored landraces are discussed

The effect of maleic hydrazide (MH) on the pre-anthesis anthers of <i>Setaria</i>.

<p>(A) Untreated control spikelet and (B) spikelet treated with 500 μM MH. (C and D) Androecium and gynoecium of control and MH-treated spikelets, respectively. (E and F) Anthers of control and MH-treated spikelets, respectively. (G and H) A representative anther of control and MH-treated spikelets, respectively. (I) In control panicles, mature seeds were observed in the spikelets. (J) Brown specks were observed as remnants of anther dehiscence in the MH-treated panicles and no seeds were set although the florets remained green. The scale bar represents 5 mm in A and B, 0.5 mm in C, D, E and F, and 0.75 mm in G and H; I and J are not to scale.</p

Seed germination in medium.

<p>(A, B) A dehuller was used to remove the seed coats of mature seeds. <i>S</i>. <i>viridis</i> seeds have two layers of seed coats, (C) outer seed coat and (D) inner seed coat. (E) Seeds after removal of both the seed coats look translucent white. (F) The dehulled seeds were washed with 70% ethanol and then with distilled water and were sterilized by incubating in a solution of 50% sodium hypochlorite containing 1 drop of Tween 20 (~2%) for 30 min. (G) The sterilized seeds were dried by blotting on filter paper. (H, I) The seeds were plated in MS medium with the embryo side facing upward. (J) All seeds germinated well in MS medium producing good root and shoot. (K) The seedlings after 10 days of plating were transplanted to the pots with soil and taken special care. (L) Immature panicles 10 to 12 days after pollination were selected for germination in MS medium. (M) Filled spikelets were chosen. (N) Selected spikelets were sterilized in 1% sodium hypochlorite solution with one drop of Tween 20 (~2%). (O) Immature embryos were dissected using sterilized scalpel and forceps, and (P) plated in MS medium. (Q) The immature embryos emerged into a seedling after 18 hrs of incubation in medium. (R) Small seedlings with well developed roots and shoots (10 to 14 days old after plating). (S) Seedlings were transplanted into pots with fine soil and covered with a translucent white cup for 2 days to allow the seedlings to adapt to the soil condition. (T) Seedlings from immature embryos could establish well in soil and (U) grew normally to maturity.</p