Engineering Lignin Nanomicroparticles for the Antiphotolysis and Controlled Release of the Plant Growth Regulator Abscisic Acid.

Lignin is the most abundant aromatic biopolymer in nature and is a major byproduct from the paper industry. The unlocking of lignin's potential for high-value applications has gained increasing attention in recent years. In this study, alkali lignin (AL), with a rigid conjugated structure and amphiphilic property, was used as a sustainable and eco-friendly encapsulation material for the protection and controlled release of photosensitive abscisic acid (ABA), an important and widely used plant growth regulator. Cetyltrimethylammonium bromide (CTAB) was used to induce the formation of AL-CTAB nanomicroparticles by self-assembly. The size and morphology of AL-CTAB particles were modified by changing the AL concentration and the dispersion agent. AL (0.3 M) dissolved in tetrahydrofuran could form a uniform size (300 nm) of particles with a regular spherical structure. Subsequently, ABA was loaded on the prepared nanomicroparticles to synthesize the capsule formulation of ABA@AL-CTAB. The controlled-release behavior and the antiphotolysis performance as well as the thermal stability of ABA@AL-CTAB were proved to be superior. Lasting inhibition of Arabidopsis and rice seed germination by ABA@AL-CTAB under light irradiations implied protection of ABA from photolysis. In addition, ABA@AL-CTAB could effectively regulate plant stomata, thereby increasing plant drought resistance. Overall, lignin is suitable for the preparation of agrochemical formulations with excellent controlled release and antiphotolysis performances.

Identification and Characterization of Major Constituents in Different-Colored Rapeseed Petals by UPLC-HESI-MS/MS.

Oilseed rape (Brassica napus L.) is the second highest yielding oil crop worldwide. In addition to being used as an edible oil and a feed for livestock, rapeseed has high ornamental value. In this study, we identified and characterized the main floral major constituents, including phenolic acids and flavonoids components, in rapeseed accessions with different-colored petals. A total of 144 constituents were identified using ultrahigh-performance liquid chromatography-HESI-mass spectrometry (UPLC-HESI-MS/MS), 57 of which were confirmed and quantified using known standards and mainly contained phenolic acids, flavonoids, and glucosinolates compounds. Most of the epicatechin, quercetin, and isorhamnetin derivates were found in red and pink petals of B. napus, while kaempferol derivates were in yellow and pale white petals. Moreover, petal-specific compounds, including a putative hydroxycinnamic acid derivative, sinapoyl malate, 1-O-sinapoyl-ß-d-glucose, feruloyl glucose, naringenin-7-O-glucoside, cyanidin-3-glucoside, cyanidin-3,5-di-O-glucoside, petunidin-3-O-ß-glucopyranoside, isorhamnetin-3-O-glucoside, kaempferol-3-O-glucoside-7-O-glucoside, quercetin-3,4'-O-di-ß-glucopyranoside, quercetin-3-O-glucoside, and delphinidin-3-O-glucoside, might contribute to a variety of petal colors in B. napus. In addition, bound phenolics were tentatively identified and contained three abundant compounds (p-coumaric acid, ferulic acid, and 8-O-4'-diferulic acid). These results provide insight into the molecular mechanisms underlying petal color and suggest strategies for breeding rapeseed with a specific petal color in the future.

[Genetic mapping of the intergenomic translocated "taigu" genic sterility gene (Ms2)].

The "Taigu" genic sterility gene Ms2 located on the short arm of the 4D chromosome of common wheat (AABBDD) originally incorporated into hexoploid triticale (AABBRR) and durum wheat (AABB) through intergenomic translocation in distant hybridization was introduced back into the genomes of common wheat. The dominant male sterility was expressed normally in the new "Taigu" genic sterile wheat carrying the intergenomically translocated Ms2, and the female fertility mechanism in its male sterile plants was normal as well. Observation of the chromosome configuration at meiosis of pollen mother cells (PMC) of the young ears of the sterile plants showed that they were euploid plants (2n = 42). No configurations different from those of the "Taigu" genic sterility gene located at the original locus were noticed of the Ms2 intergenomically translocated back into the common wheat. In systematic test crosses with marker genes the intergenomically translocated gene Ms2 was found to be linked with the dominant dwarf marker in common wheat Rht3 and, consequently, remapped and located on the short arm of the 4B chromosome of common wheat with a distance of 9.7 cM from Rht3. The new locus was designated as Ms2 (4BS). Discussions are given of the fate of Ms2 during translocation in the hexoploid triticale, the exchange of the names for 4A and 4B chromosomes in common wheat and the possible exploitation of the new locus Ms2 (4BS), and the following speculations are made: (a) In genic genes of allopolyploid organisms the donor chromosomes tend to be intergenomically translocated to their physiologically and evolutionarily close chromosomes with the same order number and the same arm; (b) it is confirmed that the 7th International Conference of Wheat Genetics was right to exchange the names between chromosomes 4A and 4B of common wheat in 1988; and (c) as a new genetic marker and a breeding tool for all the chromosome B-carrying species in the tribe of Triticeae, Ms2(4BS) may have wide application in building and expanding the gene pool of germplasm resources of various species of wheat.

TRANSPARENT TESTA 12 genes from Brassica napus and parental species: cloning, evolution, and differential involvement in yellow seed trait.

Molecular dissection of the Brassica yellow seed trait has been the subject of intense investigation. Arabidopsis thaliana TRANSPARENT TESTA 12 (AtTT12) encodes a multidrug and toxic compound extrusion (MATE) transporter involved in seed coat pigmentation. Two, one, and one full-length TT12 genes were isolated from B. napus, B. oleracea, and B. rapa, respectively, and Southern hybridization confirmed these gene numbers, implying loss of some of the triplicated TT12 genes in Brassica. BnTT12-1, BnTT12-2, BoTT12, and BrTT12 are 2,714, 3,062, 4,760, and 2,716 bp, with the longest mRNAs of 1,749, 1,711, 1,739, and 1,752 bp, respectively. All genes contained alternative transcriptional start and polyadenylation sites. BrTT12 and BoTT12 are the progenitors of BnTT12-1 and BnTT12-2, respectively, validating B. napus as an amphidiploid. All Brassica TT12 proteins displayed high levels of identity (>99%) to each other and to AtTT12 (>92%). Brassica TT12 genes resembled AtTT12 in such basic features as MatE/NorM CDs, subcellular localization, transmembrane helices, and phosphorylation sites. Plant TT12 orthologs differ from other MATE proteins by two specific motifs. Like AtTT12, all Brassica TT12 genes are most highly expressed in developing seeds. However, a range of organ specificity was observed with BnTT12 genes being less organ-specific. TT12 expression is absent in B. rapa yellow-seeded line 06K124, but not downregulated in B. oleracea yellow-seeded line 06K165. In B. napus yellow-seeded line L2, BnTT12-2 expression is absent, whereas BnTT12-1 is expressed normally. Among Brassica species, TT12 genes are differentially related to the yellow seed trait. The molecular basis for the yellow seed trait, in Brassica, and the theoretical and practical implications of the highly variable intron 1 of these TT12 genes are discussed.