Wheat (Triticum aestivum L.) quality is a major focus of wheat breeding, which is influenced by multiple factors. The Huang-Huai wheat region, one of the main wheat-producing areas in China, provides favourable conditions for cultivating wheat cultivars with strong-gluten and medium-strong-gluten. In this study, a systematic assessment of seven crucial quality traits and important genetic loci (Glu-1 and Sec-1) in 436 wheat cultivars in the Huang-Huai wheat region of China by principal component analysis (PCA) and fuzzy comprehensive evaluation (FCE) methods showed that the stability time (ST), stretch area (SA), and maximum resistance (MAXR) were identified as three key factors, which significantly influenced wheat quality. Glu-1 and Sec-1 primarily impacted these three traits and subsequently influenced wheat quality. Compared to Glu-A1 and Glu-B1, Glu-D1 has a more significant impact on the comprehensive evaluation value D, principal components PC1-PC3, and the main traits ST, SA and MAXR of PC1. Wheat cultivars carrying the high-molecular-weight glutenin subunit (HMW-GS) Dx5+Dy10 exhibited a notable improvement in ST, SA, and MAXR traits compared with those carrying HMW-GS Dx2+Dy12, suggesting that Dx5+Dy10 may enhance wheat quality by improving ST, SA, and MAXR. By combining the results of D value, GYT (genotype by yield×trait) index, and HMW-GS score, 20 high-quality and high yield wheat cultivars were identified, which can be used as elite parents for wheat quality breeding.

Softening of fleshy fruits during ripening and postharvest is a programmed physiological process that substantially impacts fruit quality and shelf life.  However, the molecular mechanism underlying peach softening remains largely unknown.  Lateral organ boundary (LOB) domain (LBD) proteins are pivotal regulators of plant growth and development.  To date, certain LOB/LBD transcription factors are seemingly implicated in fruit softening.  In this study, we identified 42 LOB/LBD genes in the peach genome.  Expression analysis showed a significant upregulation of PpLOB1 transcripts toward peach fruit ripening.  PpLOB1 was classified into Class II subgroup, and showed high sequence similarity to several softening-related LOB/LBD transcription factors.  Transient transformation assays showed that PpLOB1 positively modulates peach softening.  Further experiments demonstrated that PpLOB1 directly targets and activates the promoters of pectate lyase 1 (PpPL1) and PpPL15, thereby contributing to the regulation of fruit softening.  Additionally, PpNAP4 up-regulates PpLOB1 expression by binding to its promoter.  Meanwhile, our findings revealed that PpNAP4 and PpNAP6 cooperatively modulate the expression of PpLOB1.  Taken together, our findings revealed a novel regulatory module involving PpNAP4 and PpLOB1 that modulates peach fruit softening.  

To explore the molecular mechanisms by which autophagy contributes to pepper’s heat tolerance, we previously identified the zinc-finger protein B-BOX 9/CONSTANS-LIKE 13 (CaBBX9/CaCOL13) as an interaction partner of the autophagy related protein (ATG) CaATG8c, a core component in autophagy.  However, the involvement of CaBBX9 in both autophagy and heat tolerance remains unclear.  In this study, we further confirmed the interaction between CaBBX9 and CaATG8c and defined the interaction regions of CaBBX9 as CONSTANS, CONSTANS-Like, and TOC1 (CCT) domain and the fragment region.  The expression of CaBBX9 can be induced by heat treatment.  CaBBX9 is co-localized with CaATG8c in the nucleus and exhibits a transcriptional activity.  When the expression of CaBBX9 is silenced, the heat tolerance of pepper is enhanced, shown by the decrement of MDA content, H₂O₂ and dead cells accumulation, and relative electrolyte leakage, along with the increment of chlorophyll content and expression level of heat-tolerance-related genes.  Overexpression of CaBBX9 in tomatoes displays the opposite effects.  Taken together, we demonstrate that CaBBX9 negatively regulates the heat tolerance of peppers by exacerbating oxidative damage and inhibiting the expression of heat-related genes.  Our findings provide a new clue for guiding crop breeding for pepper tolerance to heat stress.