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Lu, J.-B.

Publications and source records attributed to Lu, J.-B..

4 recordsLinked to original sources

Sex-determination cascade orchestrates male-male pheromone synthesis in the bean bug

Volatile pheromones are vital for insect intraspecific communication, yet the genetic basis of homosexual recognition remains elusive. In the bean bug Riptortus pedestris, we show that two previously identified aggregation pheromone components, (E)-2-hexenyl-(Z)-3-hexenoate (E2HZ3H) and (E)-2-hexenyl-(E)-2-hexenoate (E2HE2H), serve as key chemosensory cues for male-male recognition during mate selection. Their biosynthesis is governed by the sex-determination cascade Rpfmd-Rpdsx. The male-specific isoform Rpdsx_M promotes pheromone production in males and induces ectopic synthesis in females upon knockdown of the feminizing switch gene Rpfmd. Knockdown of Rpdsx_M in males abolishes both compounds, prompting wild-type males to court them as if they were females. Metathoracic gland cells act as the production hub. Behaviourally, E2HZ3H or E2HE2H disrupt mating when applied to females: males avoid such females. E2HZ3H reduces female mobility in the presence of the male-derived primary aggregation pheromone tetradecyl isobutyrate (14:iBu), whereas E2HE2H shows no obvious such effect. These differential effects ensure mating accuracy. The discovery of volatile pheromones functioning in male-male recognition and of their synthesis being governed by the sex-determination cascade updates our understanding of mating accuracy in insect chemical communication.

animal behavior and cognition↗

Herbivorous insects independently evolved salivary effectors to regulate plant immunity by destabilizing the malectin-LRR RLP NtRLP4

Plants utilize on receptor-like proteins and receptor-like kinases (RLPs/RLKs) to perceive and respond to a wide variety of invading pathogens and insect herbivores. While the strategies employed by microbial pathogens to suppress plant immunity have been well characterized, it remains unclear how herbivorous insects counteract receptor-mediated defenses. Here, we show that salivary effectors evolve independently in whiteflies and planthoppers to dampen RLP4-mediated plant immunity. RLP4, as a leucine-rich repeat RLP (LRR-RLP), confers plant resistance against herbivorous insects by forming the RLP4/SOBIR1 complexes. In the whitefly Bemisia tabaci, BtRDP, the Aleyrodidae-specific salivary sheath protein, interacts with RLP4 from multiple plant species and promotes its ubiquitin-dependent degradation. Overexpression of NtRLP4 in transgenic plants exerts a detrimental effect on B. tabaci by exploiting the crosstalk between the salicylic acid (SA) and jasmonic acid (JA) pathways. Conversely, overexpression of BtRDP or silencing of NtRLP4 effectively alleviates such negative effects. In planthopper Nilaparvata lugens, the Delphacidae-restricted salivary protein NlSP104 also targets and promotes the degradation of OsRLP4 from rice plants. These findings reveal convergent evolution of salivary proteins in insects, and underscore the complex interactions between plants and herbivorous insects.

molecular biology↗

Rapid intracellular acidification is a novel plant defense response countered by the brown planthopper

The brown planthopper (BPH) is the most destructive insect pest in rice. Through a stylet, BPH secrets a plethora of salivary proteins into rice phloem cells as a crucial step of infestation. However, how various salivary proteins function in rice cells to promote insect infestation is poorly understood. Among them, one of the salivary proteins is predicted to be a carbonic anhydrase (NlCA). The survival rate of the NlCA-RNA interference (RNAi) BPH insects was extremely low on rice, indicating a vital role of this salivary protein in BPH infestation. We generated NICA transgenic rice plants and found that NlCA expressed in rice plants could restore the ability of NlCA-RNAi BPH to survive on rice. Next, we produced rice plants expressing the ratiometric pH sensor pHusion and found that NlCA-RNAi BPH induced rapid intracellular acidification of rice cells during feeding. Further analysis revealed that both NlCA-RNAi BPH feeding and artificial of lowering intracellular pH activated plant defense responses, and that NICA-mediated intracellular pH stabilization is linked to diminished defense responses, including reduced callose deposition at the phloem sieve plates and suppressed defense gene expression. Given the importance of pH homeostasis across the kingdoms of life, discovery of NICA-mediated intracellular pH modulation uncovered a new dimension in the interaction between plants and piecing/sucking insect pests. The crucial role of NICA for BPH infestation of rice suggests that NICA is a promising target for chemical or trans-kingdom RNAi-based inactivation for BPH control strategies in plants. HighlightsO_LIRapid intracellular acidification is a novel plant defense response. C_LIO_LIBrown planthopper delivers into rice tissues a major virulence protein, carbonic anhydrase (NlCA), critical for survival. C_LIO_LINlCA counters intracellular acidification to suppress plant defense. C_LIO_LIResults implicate existence of pH-responsive regulators of defense responses in the rice-brown planthopper interaction. C_LI In briefThe brown planthopper (BPH) is the most devasting insect pest in rice. Jiang et al. discovered that BPH secretes a salivary carbonic anhydrase (NICA) to regulate the intracellular pH of the rice cell to facilitate its feeding and survival on rice plants and that NICA-counters host intracellular pH acidification to diminished defense responses. These findings uncovered that intracellular pH homeostasis is a previously uncharacterized battleground in plant-insect interactions, but also open a door to future discovery of pH-responsive intracellular regulators of defense responses, which could add a new research dimension in the study of plant-biotic interactions.

plant biology↗

Whole genome sequencing of 358 brown planthoppers uncovers the landscape of their migration and dispersal worldwide

The brown planthopper (BPH), Nilaparvata lugens, is a serious migratory rice pest, which is distributed in the broad area of the tropical and temperate Asian-Pacific region. However, we know little about key aspects regarding its evolution such as how they diverged and dispersed worldwide. By resequencing and analyzing 358 BPH genomes from 92 populations across the world, we uncover the genetic relationships among their worldwide populations and the history of their global dispersal. We recovered five genetic groups representing the major population structures. Of these, Australian BPHs were shown large genetic divergence with Asian BPHs; two distinct groups have formed in South and Southeast/East Asia that show strong genetic admixture in the southwest border regions of China and west Thailand with Myanmar; two local populations in Bangladesh and Fujian province of China, respectively, unexpectedly separated with surrounding populations. We also find the genetic similarity and closely phylogenetic relationships between majority of East Asian BPHs and Indo-china peninsula BPHs, indicating that Southeast Asia mainland is the major insect sources and overwintering sites for East Asia. Our study provides important molecular evidence to address BPH evolution and other key aspects of its biology such as insecticides resistance and rice varieties virulence.

evolutionary biology↗