Previous study has shown that during zygomorphic development in garden pea (Pisum sativum L.), the organ internal (IN) asymmetry of lateral and ventral petals was regulated by a genetic locus, SYMMETRIC PETAL 1 (SYP1), while the dorsoventral (DV) asymmetry was determined by two CYC-like TCP genes or the PsCYC genes, KEELED WINGS (K) and LOBED STANDARD 1 (LST1). In this study, two novel loci, ELEPHANT EAR-LIKE LEAF 1 (ELE1) and ELE2 were characterized. These mutants exhibit a similar defect of IN asymmetry as syp1 in lateral and ventral petals, but also display pleiotropic effects of enlarged organ size. Genetic analysis showed that ELE1 and ELE2 were involved in same genetic pathway and the enlarged size of petals but not compound leaves in ele2 was suppressed by introducing k and lst1, indicating that the enlargement of dorsal petal in ele2 requires the activities of K and LST1. An experimental framework of comparative genomic mapping approach was set up to map and clone LjELE1 locus in Lotus japonicus. Cloning the ELE1 gene will shed light on the underlying molecular mechanism during zygomorphic development and further provide the molecular basis for genetic improvement on legume crops.

Li X, Zhuang LL, Ambrose M, Rameau C, Hu XH, Yang J, Luo D (2010) Genetic analysis of ele mutants and comparative mapping of ele1 locus in the control of organ internal asymmetry in garden pea. J. Integr. Plant Biol. 52(6), 528–535.

Soluble invertase was purified from pea (Pisum sativum L.) by sequential procedures entailing ammonium sulfate precipitation, DEAE-Sepharose column, Con-A- and Green 19-Sepharose affinity columns, hydroxyapatite column, ultra-filtration, and Sephacryl 300 gel filtration. The purified soluble acid (SAC) and alkaline (SALK) invertases had a pH optimum of 5.3 and 7.3, respectively. The temperature optimum of two invertases was 37 °C. The effects of various concentrations of Tris-HCl, HgCl₂, and CuSO₄ on the activities of the two purified enzymes were examined. Tris-HCl and HgCl₂ did not affect SAC activity, whereas 10 mM Tris-HCl and 0.05 mM HgCl₂ inhibited SALK activity by about 50%. SAC and SALK were inhibited by 4.8 mM and 0.6 mM CuSO₄ by 50%, respectively. The enzymes display typical hyperbolic saturation kinetics for sucrose hydrolysis. The Kms of SAC and SALK were determined to be 1.8 and 38.6 mM, respectively. The molecular masses of SAC shown by sodium dodecyl sulfate polyacrylamide gel electrophoresis and immunoblotting were 22 kDa and 45 kDa. The molecular mass of SALK was 30 kDa. Iso-electric points of the SAC and SALK were estimated to be about pH 7.0 and pH 5.7, respectively.

Kim D, Park SY, Chung Y, Park J, Lee S, Lee TK (2010) Biochemical characterization of soluble acid and alkaline invertases from shoots of etiolated pea seedlings. J. Integr. Plant Biol. 52(6), 536–548.

Root and shoot growth of Brassica campestris L. and B. juncea increased significantly (P < 0.01) with enhanced Ca²⁺ treatment along with 60 mM NaCl in the root medium. The maximum fresh mass of shoot and root in B. juncea was recorded at 10 mM Ca²⁺ concentration. The relative growth rate of shoot of both species reached its maximum at 8 mM of Ca²⁺ concentration. Average rate of Ca²⁺ intake (Î_Ca) was higher in B. juncea than B. campestris. In B. juncea, the average transport of Ca²⁺ to shoot increased by 19%, 38%, 119%, 125% and 169% compared with the control. Furthermore specific utilization rate of Ca²⁺ was higher in B. juncea than B. campestris. In B. campestris it increased by 9%, 32%, 41% and 59% at 4, 6, 8, and 10 mM of calcium in comparison to 2 mM Ca²⁺ treatment. At 4, 6, 8 and 10 mM of Ca²⁺ application, the increase in the leaf area ratio was 10, 17, 23 and 30%, respectively. In the shoot and root portions of B. campestris and B. juncea, Ca²⁺ had a linear relationship with potassium and sulfur, whereas it was in antagonism with sodium ion.

Badr-uz-Zaman, Salim M, Asghar R (2010) Role of Ca2+ on growth of Brassica campestris L. and B. juncea (L.) Czern & Coss. under Na+ stress. J. Integr. Plant Biol. J. Integr. Plant Biol. 52(6), 549–555.

An endoplasmic reticulum-localized tomato ω-3 fatty acid desaturase gene (LeFAD3) was isolated. The antisense tomato plants were obtained under the control of the cauliflower mosaic virus 35S promoter (35S-CaMV). Northern blot analysis confirmed that the expression of LeFAD3 was inhibited in the tomato genome. Levels of 18:3 decreased and correspondingly levels of 18:2 increased in total lipids of leaves and roots. After heat stress, the fresh weight of the aerial parts of antisense transgenic plants was higher than that of the wild type (WT) plants. The membrane system ultrastructure of chloroplasts in leaf cells and all of the subcellular organelles in the root tips of transgenic plants remained more intact than those of WT. Relative electric conductivity increased less in transgenic plants than in WT. Under heat stress, the maximal photochemical efficiency of photosystem II (Fv/Fm) and the O₂ evolution rate decreased more in WT than in transgenic plants. These results suggested that the depletion of LeFAD3 increased the saturation of fatty acids and alleviated high temperature stress.

Wang HS, Yu C, Tang XF, Wang LY, Dong XC, Meng QW (2010) Antisense-mediated depletion of tomato endoplasmic reticulum omega-3 fatty acid desaturase enhances thermal tolerance. J. Integr. Plant Biol. 52(6), 568–577.

The present study was conducted to identify quantitative trait loci (QTLs) for leaf size traits in IR64 introgression lines (INLs). For this purpose, selected F₂ populations derived from crosses between recurrent parent IR64 and its derived INLs, unique for leaf length and leaf width, were used to confirm QTLs. A total of eight QTLs, mapped on three chromosomes, were identified for the four leaf size traits in six F₂ populations. A QTL for leaf length, qLLnpt-1, in HKL69 was identified around simple sequence repeat (SSR) marker RM3709 on chromosome 1. Two QTLs for flag leaf length, qFLLnpt-2 and qFLLnpt-4, in HFG39 were indentified on chromosomes 2 and 4, respectively. For flag leaf width, a QTL, qFLWnpt-4, in HFG39 was identified around RM17483 on chromosome 4. While another QTL for flag leaf width, qFLWnpt-1, in HFG27 was identified around RM3252 on chromosome 1. A QTL for leaf width, qLWnpt-2, in HKL75 was identified around RM7451 on chromosome 2. For leaf width, two QTLs, qLWnpt-4a, qLWnpt-4b, in HKL48 and HKL99 were identified around RM7208 and RM6909, respectively on chromosome 4. Results from this study suggest the possibilities to use marker-assisted selection and pyramiding these QTLs to improve rice water productivity.

Farooq M, Tagle AG, Santos RE, Ebron LA, Fujita D, Kobayashi N (2010) Quantitative Trait Loci mapping for leaf length and leaf width in rice cv. IR64 derived lines. J. Integr. Plant Biol. 52(6), 578–584.

The diverse functions of phosphoenolpyruvate carboxylase (PEPCase; EC 4.1.1.31) in C₃ plants are not as well understood as in C₄ plants. To investigate the functions of PEPCase in C₃ plants, rapeseed (Brassica napus L.) PEPCase gene (referred to as BNPE15) was silenced by the RNA interference (RNAi) technique. Under normal growth conditions, no significant difference in lipid content and fatty acid composition were found between wild-type (WT) and transgenic rapeseed plants. However, when these plants were subjected to osmotic stress induced by osmoticum polyethylene glycol (PEG-6000), membrane permeability and membrane lipid peroxidization in roots and leaves of transgenic plants were higher than those of WT plants. It suggested that transgenic plants are more susceptible to osmotic stress than WT plants. Taken together, the results showed that the suppression of PEPCase by RNAi leads to susceptibility to osmotic stress in rapeseed, and PEPCase is involved in the response of C₃ plants to environmental stress.

Chen M, Tang Y, Zhang J, Yang M, Xu Y (2010) RNA interference-based suppression of phosphoenolpyruvate carboxylase results in susceptibility of rapeseed to osmotic stress. J. Integr. Plant Biol. 52(6), 585–592.

Delayed selfing could provide ovules with an opportunity to be fertilized as a means of "pollination assurance" before the flowers wilt. It could, thus, be regarded as an adaptation to unpredictable pollinator environments. Within the alpine biennial Gentianopsis paludosa, the showy flowers and herkogamy at the early stage of a flower's life cycle may favor outcrossing. As the flower ages, anthers contact the central stigma due to the elongation of all filaments, resulting in autonomous selfing. Flower visitors are extremely rare in a high altitude population; and examination of the mating system indicates that G. paludosa is self-pollinated under natural conditions in this population. While at the lower altitude, the bumblebee visitation rate is relatively high but possibly unreliable. Stigma receptivity is the highest on the third day of anthesis, and decreases thereafter. Pollen viability is the highest when flowers open, and gradually decreases later. Self-pollination of G. paludosa occurs at the late stage of a flower's lifecycle when stigma receptivity and pollen viability have both decreased, suggesting delayed selfing and assurance of seed production. This delayed selfing could assure seed production under the constraints of pollinator scarcity, but ensure outcrossing when pollinators were available. Such a flexible pollination mechanism is highly adaptive in the alpine environment of the Qinghai-Tibetan Plateau.

Duan YW, Dafni A, Hou QZ, He YP, Liu JQ (2010) Delayed selfing in an alpine biennial Gentianopsis paludosa (Gentianaceae) in the Qinghai-Tibetan Plateau. J. Integr. Plant Biol. 52(6), 593–599.